Ultimatum in the context of "Abdülmecid I"

On 3 September 1939—two days after the German invasion of Poland—France declared war on Nazi Germany according to its defensive treaty with Poland, when France's ultimatum to Germany, issued the previous day, expired at 17:00. This occurred hours after the United Kingdom declaration of war on Germany.

Between 28 June and 3 July 1940, the Soviet Union occupied Bessarabia and Northern Bukovina, following an ultimatum made to Romania on 26 June 1940 that threatened the use of force. Those regions, with a total area of 50,762 km (19,599 sq mi) and a population of 3,776,309 inhabitants, were incorporated into the Soviet Union. On 26 October 1940, six Romanian islands on the Chilia branch of the Danube, with an area of 23.75 km (9.17 sq mi), were also occupied by the Soviet Army.

The Soviet Union had planned to accomplish the annexation with a full-scale invasion, but the Romanian government, responding to the Soviet ultimatum delivered on 26 June, agreed to withdraw from the territories to avoid a military conflict. The use of force had been made illegal by the Conventions for the Definition of Aggression in July 1933, but from an international legal standpoint, the new status of the annexed territories was eventually based on a formal agreement through which Romania consented to the retrocession of Bessarabia and cession of Northern Bukovina. As it was not mentioned in the ultimatum, the annexation of the Hertsa region was not consented to by Romania, and the same is true of the subsequent Soviet occupation of the Danube islands. On 24 June, Nazi Germany, which had acknowledged the Soviet interest in Bessarabia in a secret protocol to the 1939 Molotov–Ribbentrop Pact, had been made aware prior to the planned ultimatum but did not inform the Romanian authorities and was unwilling to provide support. On 22 June, France, a guarantor of Romanian borders, fell to Nazi advances. This is considered to be an important factor in the Soviets' decision to issue the ultimatum. The Soviet invasion of Bukovina in 1940 violated the Molotov-Ribbentrop Pact, since it went beyond the Soviet sphere of influence that had been agreed with the Axis.

The Potsdam Declaration, or the Proclamation Defining Terms for Japanese Surrender, was a statement that called for the surrender of all Japanese armed forces during World War II. On July 26, 1945, United States President Harry S. Truman, United Kingdom Prime Minister Winston Churchill, and President of China Chiang Kai-shek issued the document, which outlined the terms of surrender for the Empire of Japan, as agreed upon at the Potsdam Conference. The ultimatum stated that, if Japan did not surrender, it would face "prompt and utter destruction."

The German invasion of Belgium was a military campaign which began on 4 August 1914. On 24 July, the Belgian government had announced that if war came it would uphold its neutrality. The Belgian government mobilised its armed forces on 31 July and a state of heightened alert (Kriegsgefahr) was proclaimed in Germany. On 2 August, the German government sent an ultimatum to Belgium, demanding passage through the country and German forces invaded Luxembourg. Two days later, the Belgian government refused the German demands and the British government guaranteed military support to Belgium. The German government declared war on Belgium on 4 August; German troops crossed the border and began the Battle of Liège.

German military operations in Belgium were intended to bring the 1st, 2nd and 3rd Armies into positions in Belgium from which they could invade France, which, after the fall of Liège on 7 August, led to sieges of Belgian fortresses along the river Meuse at Namur and the surrender of the last forts (16–17 August). The government abandoned the capital, Brussels, on 17 August and after fighting on the Gete river, the Belgian field army withdrew westwards to the National Redoubt at Antwerp on 19 August. Brussels was occupied the following day and the siege of Namur began on 21 August.

A hostage is a person seized by an abductor in order to compel another party, one which places a high value on the liberty, well-being and safety of the person seized—such as a relative, employer, law enforcement, or government—to act, or refrain from acting, in a certain way, often under threat of serious physical harm or death to the hostage(s) after expiration of an ultimatum. The Encyclopædia Britannica Eleventh Edition defines a hostage as "a person who is handed over by one of two belligerent parties to the other or seized as security for the carrying out of an agreement, or as a preventive measure against certain acts of war."

A party who seizes one or more hostages is known as a hostage-taker; if the hostages are present voluntarily, then the receiver is known as a host.

The Godesberg Memorandum is a document issued by Adolf Hitler in the early hours of 24 September 1938 concerning the Sudetenland and amounting to an ultimatum addressed to the government of Czechoslovakia.

It was named after Bad Godesberg, where Hitler had met Neville Chamberlain for long talks on 23 September continuing into the next day.

On 17 December 2021, during the prelude to the Russian invasion of Ukraine, Russia published a list of demands to the West for security guarantees in the form of two draft treaties with the North Atlantic Treaty Organization (NATO) and the United States. The proposals included a ban on Ukraine and other ex-Soviet countries from joining NATO, and a roll-back in deployments of NATO troops and weapons in Central and Eastern Europe. Russia had long been concerned with the decline in its self-regarded sphere of influence in the former Soviet republics, which were aligning themselves with the West economically and politically, and had been dissatisfied with the existing security architecture and NATO expansion. The demands, issued during a period of high tensions during which about 100,000 Russian troops were massed on Ukraine's borders, were widely seen as an ultimatum and attempt by Russia to exert pressure and influence on Western countries. The main demands were rejected by NATO and the United States on 26 January 2022; the Russian invasion of Ukraine followed less than a month later on 24 February.

The United Kingdom and the British Empire entered World War I on 4 August 1914, when King George V declared war after the expiry of an ultimatum to the German Empire. The official explanation focused on protecting Belgium as a neutral country; the main reason, however, was to prevent a French defeat that would have left Germany in control of Western Europe. The Liberal Party was in power with prime minister H. H. Asquith and foreign minister Edward Grey leading the way. The Liberal cabinet made the decision, although the party had been strongly anti-war until the last minute. The Conservative Party was pro-war. The Liberals knew that if they split on the war issue, they would lose control of the government to the Conservatives.