World War I in the context of Indianapolis 500

Yugoslavia was a state concept among the South Slavic intelligentsia and later popular masses from the 19th to early 20th centuries that culminated in its realization after the 1918 collapse of Austria-Hungary at the end of World War I and the formation of the Kingdom of Serbs, Croats and Slovenes. However, from as early as 1922 onward, the kingdom was better known colloquially as Yugoslavia (or similar variants); in 1929 the name was made official when the country was formally renamed the "Kingdom of Yugoslavia".

The creation of Yugoslavia has been described as expansionist and irredentist in its approach to foreign policy, and federalist in its approach to politics, with power centralised in the Serb-dominated government. Despite the idea of Yugoslavism having promoted equality among the South Slavic ethnic groups, the new Yugoslav state was ruled by the Serbian Karađorđević dynasty that sought to implement pro-Serb policies throughout the country, leaving minority groups like Croatians and Bosniaks (Bosnian Muslims) not feeling represented in the new government. This led to the formation of opposition parties that became identified with particular ethnic groups within the country. Similarly, the concept of Yugoslavism became associated with the idea of a South Slavic nation dominated by Serbs; and in some instances, forced cultural assimilation policies introduced by the Serb-led Yugoslav government. However, the creation of Yugoslavia remained popular even among non-Serbs, as it was seen as a means of unification for South Slavs to protect themselves against non-Slavic powers such as Fascist Italy.

Balkanization or Balkanisation is the process involving the fragmentation of an area, country, or region into multiple smaller, and often hostile, independent states. It is usually caused by differences in ethnicity, culture, religion, and geopolitical interests.

The term was first coined in the early 20th century, and found its roots in the depiction of events during the Balkan Wars (1912–1913) and World War I (1914–1918), specifically referring to incidents that transpired earlier in the Balkan Peninsula.

Montenegro is a country in Southeast Europe, on the Balkan Peninsula. Its 25 municipalities have a total population of 633,158 people in an area of 13,883 km (5,360 sq mi). It is bordered by Serbia to the northeast, Bosnia and Herzegovina to the northwest, Kosovo to the east, Albania to the southeast, and Croatia to the west, and has a coastline along the Adriatic Sea to the southwest. The capital and largest city is Podgorica, while Cetinje is the Old Royal Capital and cultural centre.

Before the arrival of the Slav peoples in the Balkans in the 6th and 7th centuries CE, the area now known as Montenegro was inhabited principally by people known as Illyrians.During the Early Medieval period, three principalities were located on the territory of modern-day Montenegro: Duklja, roughly corresponding to the southern half; Travunia, the west; and Rascia proper, the north. The Principality of Zeta emerged in the 14th and 15th centuries. From the late 14th century to the late 18th century, large parts of southern Montenegro were ruled by the Venetian Republic and incorporated into Venetian Albania. The name Montenegro was first used to refer to the country in the late 15th century. After falling under Ottoman Empire rule, Montenegro gained semi-autonomy in 1696 under the rule of the House of Petrović-Njegoš, first as a theocracy and later as a secular principality. Montenegro's independence was recognised by the Great Powers at the Congress of Berlin in 1878. In 1910, the country became a kingdom. After World War I, the kingdom became part of Yugoslavia. Following the breakup of Yugoslavia, the republics of Serbia and Montenegro together proclaimed a federation. In June 2006 Montenegro declared its independence following a referendum.

Skopje is the capital and largest city of North Macedonia. It lies in the northern part of the country, in the Skopje Valley along the Vardar River, and is the political, economic, and cultural centre of the country. As of the 2021 census, the city had a population of 526,502. Skopje covers 571.46 km (220.64 sq mi) and includes both urban and rural areas, bordered by several municipalities and close to the borders of Kosovo and Serbia.

The area of Skopje has been continuously inhabited since at least the Chalcolithic period. The city — known as Scupi at the time — was founded in the late 1st century during the rule of Domitian, and abandoned in 518 after an earthquake destroyed the city. It was rebuilt under Justinian I. It became a significant settlement under the First Bulgarian Empire, the Serbian Empire (when it served briefly as a capital), and later under the Ottoman Empire, which ruled the city for over five centuries. In 1912, following the Balkan Wars, Skopje was annexed by the Kingdom of Serbia. It became part of Yugoslavia after World War I and, following World War II, became the capital of the Socialist Republic of Macedonia, one of its constituent republics. In 1963, a major earthquake devastated the city, after which it was largely rebuilt with international assistance. Skopje became the capital of independent North Macedonia in 1991.

The Kingdom of Serbia was a country located in the Balkans which was created when the ruler of the Principality of Serbia, Milan I, was proclaimed king in 1882. Since 1817, the Principality was ruled by the Obrenović dynasty (replaced by the Karađorđević dynasty for a short time). The Principality of Serbia, under the suzerainty of the Turkish Empire, de facto achieved full independence when the very last Ottoman troops left Belgrade in 1867. The Congress of Berlin in 1878 recognized the formal independence of the Principality of Serbia, and in its composition Nišava, Pirot, Toplica and Vranje districts entered the South part of Serbia.

In 1882, Serbia was elevated to the status of a kingdom, initially maintaining a foreign policy friendly to Austria-Hungary before turning to the Russian Empire and France following a coup d'état in 1903. Between 1912 and 1913, Serbia greatly enlarged its territory through engagement in the First and Second Balkan Wars – Sandžak-Raška, Kosovo Vilayet and Vardar Macedonia were annexed. At the end of World War I in 1918 it united with Vojvodina and the Kingdom of Montenegro, and in December 1918 it merged with the newly created State of Slovenes, Croats and Serbs to form the Kingdom of Serbs, Croats and Slovenes (later known as Kingdom of Yugoslavia) under the continued rule of the Karađorđević dynasty.

Romania is a country located at the crossroads of Central, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to the east, and the Black Sea to the southeast. It has a mainly continental climate, and an area of 238,397 km (92,046 sq mi) with a population of 19 million people. Romania is the twelfth-largest country in Europe and the sixth-most populous member state of the European Union. Europe's second-longest river, the Danube, empties into the Danube Delta in the southeast of the country. The Carpathian Mountains cross Romania from the north to the southwest and include Moldoveanu Peak, at an altitude of 2,544 m (8,346 ft). Bucharest is the country's capital, largest urban area, and financial centre. Other major urban areas include Cluj-Napoca, Timișoara, Iași, Constanța and Brașov.

Settlement in the territory of modern Romania began in the Lower Paleolithic, later becoming the Dacian Kingdom before Roman conquest and Romanisation. The modern Romanian state was formed in 1859 with the unification of Moldavia and Wallachia under Alexandru Ioan Cuza, becoming the Kingdom of Romania in 1881 under Carol I of Romania. Romania gained independence from the Ottoman Empire in 1877, formalised by the Treaty of Berlin. After World War I, Transylvania, Banat, Bukovina, and Bessarabia joined the Old Kingdom, forming Greater Romania, which reached its largest territorial extent. In 1940, under Axis pressure, Romania lost territories to Hungary, Bulgaria, and the Soviet Union. Following the 1944 Romanian coup d'état, Romania switched sides to join the Allies. After World War II, it regained Northern Transylvania through the Paris Peace Treaties. Under Soviet occupation, King Michael I was forced to abdicate, and Romania became a socialist republic and Warsaw Pact member. After the uniquely violent Romanian revolution in December 1989, Romania began a transition to liberal democracy and a market economy.

Minorities in Turkey form a substantial part of the country's population, representing an estimated 25 to 28 percent of the population. Historically, in the Ottoman Empire, Islam was the official and dominant religion, with Muslims having more rights than non-Muslims, whose rights were restricted. Non-Muslim (dhimmi) ethno-religious groups were legally identified by different millet ("nations").

Following the end of World War I and the dissolution of the Ottoman Empire, all Ottoman Muslims were made part of the modern citizenry or the Turkish nation as the newly founded Republic of Turkey was constituted as a Muslim nation state. While Turkish nationalist policy viewed all Muslims in Turkey as Turks without exception, non-Muslim minority groups, such as Jews and Christians, were designated as "foreign nations" (dhimmi). Conversely, Turk (term for Muslims) was used to denote all groups in the region who had been Islamized under Ottoman rule, especially Muslim Albanians and Slavic Muslims.

Antalya is one of the largest cities in Turkey and the capital of Antalya Province, the fifth-most populous province. Recognized as the "capital of tourism" in Turkey and a pivotal part of the Turkish Riviera, Antalya sits on Anatolia's southwest coast, flanked by the Taurus Mountains. The urban population of the city is around 1.5 million, with a provincial population of 2,722,103.

The city was formerly known as Attalia and was founded in around 200 BC by King Attalus II of Pergamon. Attalia was soon conquered by the Romans. Roman rule saw the city thrive, including the construction of several new monuments, such as Hadrian's Gate, and the flourishing of nearby ancient cities such as Patara, Xanthos and Myra in the Lycia region; Perga, Aspendos and Side in Pamphylia; and Sagalassos, Antioch and Termessos in Pisidia. These cities were already significant centers before Roman influence. Antalya has changed hands several times, including to the Seljuk Empire in 1207 and an expanding Ottoman Empire in 1391. Ottoman rule brought relative peace and stability for the next five hundred years. The city was occupied by Italy for three years in the aftermath of World War I, but was returned to Turkey during the Turkish War of Independence.

Jordan, officially the Hashemite Kingdom of Jordan, is a country in the Southern Levant region of West Asia. Jordan is bordered by Syria to the north, Iraq to the east, Saudi Arabia to the south, and both Israel and Palestine (West Bank) to the west. The Jordan River, flowing into the Dead Sea, is located along the country's western border within the Jordan Rift Valley. Jordan has a small coastline along the Red Sea in its southwest, separated by the Gulf of Aqaba from Egypt. Amman is the country's capital and largest city, as well as the most populous city in the Levant.

Inhabited by humans since the Paleolithic period, three kingdoms developed in Transjordan during the Iron Age: Ammon, Moab and Edom. In the third century BC, the Arab Nabataeans established their kingdom centered in Petra. The Greco-Roman period saw the establishment of several cities in Transjordan that comprised the Decapolis. After the end of Byzantine rule, the region became part of the Islamic caliphates of the Rashidun, Umayyad, Abbasid, and the Ottoman. Following the 1916 Great Arab Revolt during World War I, former Ottoman Syria was partitioned, leading to the establishment of the Emirate of Transjordan in 1921, which became a British protectorate. In 1946, Jordan gained independence and became officially known as the Hashemite Kingdom of Jordan. Jordan captured and annexed the West Bank during the 1948 Palestine war until it was occupied by Israel in 1967. Jordan renounced its claim to the territory to the Palestinians in 1988 and signed a peace treaty with Israel in 1994.

Palestine, officially the State of Palestine, is a country in West Asia. It encompasses the Israeli-occupied West Bank, including East Jerusalem, and the Gaza Strip, collectively known as the Palestinian territories. The territories share the vast majority of their borders with Israel, with the West Bank bordering Jordan to the east and the Gaza Strip bordering Egypt to the southwest. It has a total land area of 6,020 square kilometres (2,320 sq mi) while its population exceeds five million. Its proclaimed capital is Jerusalem, while Ramallah serves as its de facto administrative center. Gaza was its largest city prior to evacuations in 2023.

Situated at a continental crossroad, the Palestine region was ruled by various empires and experienced various demographic changes from antiquity to the modern era. It was treading ground for the Nile and Mesopotamian armies and merchants from North Africa, China and India. The region has religious significance. The ongoing Israeli–Palestinian conflict dates back to the rise of the Zionist movement, supported by the United Kingdom during World War I. The war saw Britain occupying Palestine from the Ottoman Empire, where it set up Mandatory Palestine under the auspices of the League of Nations. Increased Jewish immigration led to intercommunal conflict between Jews and Palestinian Arabs, which escalated into a civil war in 1947 after a proposed partitioning by the United Nations was rejected by the Palestinians and other Arab nations.

The aftermath of World War I saw far-reaching and wide-ranging cultural, economic, and social change across Europe, Asia, Africa, and in areas outside those that were directly involved. Four empires collapsed due to the war, old countries were abolished, new ones were formed, boundaries were redrawn, international organizations were established, and many new and old ideologies took a firm hold in people's minds. Additionally, culture in the nations involved was greatly changed. World War I also had the effect of bringing political transformation to most of the principal parties involved in the conflict, transforming them into electoral democracies by bringing near-universal suffrage for the first time in history, as in Germany (1919 German federal election), the United Kingdom (1918 United Kingdom general election), and the United States (1920 United States presidential election).

The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States also asserts sovereignty over five major island territories and various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's third-largest land area and third-largest population, exceeding 340 million.

Paleo-Indians first migrated from North Asia to North America over 12,000 years ago, and formed various civilizations. Spanish colonization established Spanish Florida in 1513, the first European colony in what is now the continental United States. British colonization followed with the 1607 settlement of Virginia, the first of the Thirteen Colonies. Enslavement of Africans was practiced in all colonies by 1770 and supplied most of the labor for the Southern Colonies' plantation economy. Clashes with the British Crown over taxation and lack of parliamentary representation sparked the American Revolution, leading to the Declaration of Independence on July 4, 1776. Victory in the 1775–1783 Revolutionary War brought international recognition of U.S. sovereignty and fueled westward expansion, dispossessing native inhabitants. As more states were admitted, a North–South division over slavery led the Confederate States of America to attempt secession and fight the Union in the 1861–1865 American Civil War. With the United States' victory and reunification, slavery was abolished nationally. By 1900, the country had established itself as a great power, a status solidified after its involvement in World War I. Following Japan's attack on Pearl Harbor in 1941, the U.S. entered World War II. Its aftermath left the U.S. and the Soviet Union as rival superpowers, competing for ideological dominance and international influence during the Cold War. The Soviet Union's collapse in 1991 ended the Cold War, leaving the U.S. as the world's sole superpower.

Conquest involves the annexation or control of another entity's territory through war or coercion. Historically, conquests occurred frequently in the international system, and there were limited normative or legal prohibitions against conquest.

The onset and diffusion of nationalism (the belief that nation and state should be congruent), especially in the 19th century, made the idea of conquest increasingly unacceptable to popular opinion. Prohibitions against conquest were codified with the establishment of the League of Nations following World War I and of the United Nations at the end of World War II.

Norway, officially the Kingdom of Norway, is a Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of Norway. Bouvet Island, located in the Subantarctic, is a dependency, and not a part of the Kingdom; Norway also claims the Antarctic territories of Peter I Island and Queen Maud Land. Norway has a population of 5.6 million. Its capital and largest city is Oslo. The country has a total area of 385,207 square kilometres (148,729 sq mi). The country shares a long eastern border with Sweden, and is bordered by Finland and Russia to the northeast. Norway has an extensive coastline facing the Skagerrak strait, the North Atlantic Ocean, and the Barents Sea. In 2024, Norway was ranked the seventh happiest country in the world.

The unified kingdom of Norway was established in 872 as a merger of petty kingdoms and has existed continuously for 1,152–1,153 years. From 1537 to 1814, Norway was part of Denmark–Norway, and, from 1814 to 1905, it was in a personal union with Sweden. Norway was neutral during the First World War, and in the Second World War until April 1940 when it was invaded and occupied by Nazi Germany until the end of the war.

Modernism was an early 20th-century movement in literature, visual arts, performing arts, and music that emphasized experimentation, abstraction, and subjective experience. Philosophy, politics, architecture, and social issues were all aspects of this movement. Modernism centered around beliefs in a "growing alienation" from prevailing "morality, optimism, and convention" and a desire to change how "human beings in a society interact and live together".

The modernist movement emerged during the late 19th century in response to significant changes in Western culture, including secularization and the growing influence of science. It is characterized by a self-conscious rejection of tradition and the search for newer means of cultural expression. Modernism was influenced by widespread technological innovation, industrialization, and urbanization, as well as the cultural and geopolitical shifts that occurred after World War I. Artistic movements and techniques associated with modernism include abstract art, literary stream-of-consciousness, cinematic montage, musical atonality and twelve-tonality, modern dance, modernist architecture, and urban planning.

The United Nations Security Council (UNSC) is one of the six principal organs of the UN system and is the primary organ charged with ensuring international peace and security. Its powers as outlined in the UN Charter include authorizing military action, establishing peacekeeping operations, recommending the admission of new members to the UN General Assembly, approving any changes to the Charter, and enacting international sanctions. Chapter VII of the UN Charter gives the Security Council the power to identify threats to international peace and security and to authorize responses, including the use of force. Security Council resolutions adopted under Chapter VII are binding on UN members and are therefore a source of international law. The Security Council is the only UN body with the authority to issue resolutions that are binding on its member states.

Like the United Nations as a whole, the Security Council was created after World War II in 1945 in the hope of preventing future wars and maintaining world peace, as the League of Nations had been formed following World War I. It held its first session on 17 January 1946 but was largely paralyzed in the following decades by the Cold War between the United States and the Soviet Union (and their allies). Nevertheless, it authorized military interventions in the Korean War, the Congo Crisis, and peacekeeping missions in Cyprus, West New Guinea, and the Sinai Peninsula. With the collapse of the Soviet Union, UN peacekeeping efforts increased dramatically in scale, with the Security Council authorizing major military and peacekeeping missions in Kuwait, Namibia, Cambodia, Bosnia and Herzegovina, Rwanda, Somalia, Sudan, and the Democratic Republic of the Congo.

A monarchy is a hereditary form of government in which political power is legally passed on to the family members of the monarch, a head of state who rules for life. While monarchs gain their power depending on specific succession laws, they can also gain their authority via election.

Monarchies were the most common form of government until the 20th century, when republics replaced many monarchies, notably at the end of World War I. As of 2025, forty-three sovereign nations in the world have a monarch, including fifteen Commonwealth realms that share King Charles III as their head of state. Other than that, there is a range of sub-national monarchical entities. Most of the modern monarchies are constitutional monarchies, retaining under a constitution unique legal and ceremonial roles for monarchs exercising limited or no political power, similar to heads of state in a parliamentary republic.

Pirin Macedonia or Bulgarian Macedonia (Bulgarian: Пиринска Македония; Българска Македония) (Pirinska Makedoniya or Bulgarska Makedoniya), which today is in southwestern Bulgaria, is the third-biggest part of the geographical region of Macedonia. This part coincides with the borders of Blagoevgrad Province, as well as the surrounding area of Barakovo from Kyustendil Province. After World War I, Strumica and the surrounding area were broken away from the region and were ceded to Yugoslavia.

It covers an area of about 6,798 km, which is 10.18% of the geographical region of Macedonia. One of the regional centers is Blagoevgrad. The region borders Kyustendil Province and Sofia Province to the north, Pazardzhik Province and Smolyan Province to the east, Greece to the south, and North Macedonia to the west. The population is estimated around 290,000 people.

Franklin Delano Roosevelt (January 30, 1882 – April 12, 1945), also known as FDR, was the 32nd president of the United States, serving from 1933 until his death in 1945. He is the longest-serving U.S. president, as well as the only one to have served more than two terms. His first two terms were centered on combating the Great Depression, while his third and fourth saw him shift his focus to U.S. involvement in World War II. A member of the Democratic Party, Roosevelt previously served in the New York State Senate from 1911 to 1913, the assistant secretary of the Navy under President Woodrow Wilson from 1913 to 1920, and as the 44th governor of New York from 1929 to 1932.

Born into the prominent Delano and Roosevelt families in Hyde Park, New York, Roosevelt graduated from Harvard University with a Bachelor of Arts. He entered Columbia Law School in 1904, but dropped out in 1907 after passing the New York bar examination. Roosevelt was elected to the New York State Senate from 1911 to 1913 before serving as the assistant secretary of the Navy under President Wilson during World War I. Roosevelt was James M. Cox's running mate on the Democratic ticket in the 1920 presidential election, which Cox lost to Republican nominee Warren G. Harding. In 1921, Roosevelt contracted a paralytic illness that permanently paralyzed his legs. However, he returned to the public office upon being elected governor of New York in 1928, partly through the encouragement of his wife Eleanor, and during his tenure as governor of New York, he promoted programs to combat the Great Depression. After receiving the Democratic nomination, Roosevelt defeated President Herbert Hoover in a landside victory in the 1932 presidential election.

The Hague Conventions of 1899 and 1907 are a series of international treaties and declarations negotiated at two international peace conferences at The Hague in the Netherlands. Along with the Geneva Conventions, the Hague Conventions were among the first formal statements of the laws of war and war crimes in the body of secular international law. A third conference was planned for 1914 and later rescheduled for 1915, but it did not take place because of the start of World War I.