AK-74 in the context of "Soviet Armed Forces"

The "little green men" (Russian: зелёные человечки, romanized: zelyonye chelovechki; Ukrainian: зелені чоловічки, romanized: zeleni cholovichky) were Russian soldiers who were masked and wore unmarked uniforms upon the outbreak of the Russo-Ukrainian War in 2014. They were active just before and during the Russian annexation of Crimea and carried regular weapons and equipment, but were always masked and wore distinctly unmarked green military fatigues. Russia, which had been denying any involvement in Ukraine prior to the annexation, used these little green men to give it plausible deniability on the international stage.

Between February and March 2014, these unmarked Russian soldiers occupied and blockaded the Simferopol International Airport, most of Ukraine's Crimean military bases, and the Supreme Council of Crimea. The name has also sometimes been used to refer to Russian troops during the War in Donbas; the Kremlin stated that no Russian troops were active in the region, but many little green men were operating in this region while disguised as pro-Russian separatists.

An assault rifle is a select fire rifle that uses an intermediate-rifle cartridge and a detachable magazine. Assault rifles were first put into mass production and accepted into widespread service during World War II. The first assault rifle to see major usage was the German StG 44, a development of the earlier Mkb 42. While immediately after World War II, NATO countries were equipped with battle rifles, the development of the M16 rifle during the Vietnam War prompted the adoption of assault rifles by the rest of NATO. By the end of the 20th century, assault rifles had become the standard weapon in most of the world's armies, replacing full-powered rifles and submachine guns in most roles. The two most successful modern assault rifles are the AK-47 and the M16 designs and their derivatives.

A bolt is the part of a repeating, breechloading firearm that blocks the rear opening (breech) of the barrel chamber while the propellant burns, and moves back and forward to facilitate loading/unloading of cartridges from the magazine. The firing pin and extractor are often integral parts of the bolt. The terms "breechblock" and "bolt" are often used interchangeably or without a clear distinction, though usually, a bolt is a type of breechblock that has a nominally circular cross-section.

In most automatic firearms that use delayed blowback, recoil, or gas operation, the bolt itself is housed within the larger bolt carrier group (BCG), which contains additional parts that receives rearward push from a gas tube (direct impingement) or a gas piston (short-stroke or long-stroke piston) system. The slide of a self-loading pistol contains the same components and serves similar functions.

The 7.62×39 mm (also called 7.62 Soviet, formerly .30 Russian Short) round is a rimless bottlenecked intermediate cartridge of Soviet origin. The cartridge is widely used due to the global proliferation of the AK-47 rifle and related Kalashnikov-pattern rifles, the SKS semi-automatic rifle, and the RPD/RPK light machine guns.

The AK-47 was designed shortly after World War II, later becoming the AKM because the production of sheet metal receivers had issues when first initiated. This weapon is now the world's most widespread military-pattern rifle. The cartridge remained the Soviet standard until the 1970s. It was partly replaced in Soviet service by the 5.45×39mm cartridge, which was introduced with the new AK-74 rifle, and continues in service with the modernized current-issue Russian Armed Forces AK-74M service rifle, as well as the AK-12 rifle. In the 21st century, the 7.62×39 mm remains a common service rifle chambering, including for newly developed rifles like the AK-15.

Mikhail Timofeyevich Kalashnikov (10 November 1919 – 23 December 2013) was a Soviet and Russian lieutenant general, inventor, military engineer, writer, and small arms designer. He is most famous for developing the AK-47 assault rifle and its improvements, the AKM and AK-74, as well as the RPK light machine gun and PK machine gun.

Kalashnikov was, according to himself, a self-taught tinkerer who combined innate mechanical skills with the study of weaponry to design arms that achieved battlefield ubiquity. Even though Kalashnikov felt sorrow at the weapons' uncontrolled distribution, he took pride in his inventions and in their reputation for reliability, emphasizing that his rifle is "a weapon of defense" and "not a weapon for offense".

The two most common assault rifles in the world are the Soviet AK-47 and the American M16. These Cold War-era rifles have been used in conflicts both large and small since the 1960s. They are used by military, police, security forces, revolutionaries, terrorists, criminals, and civilians alike and will most likely continue to be used for decades to come. As a result, they have been the subject of countless comparisons and endless debate.

The AK-47 was finalized, adopted, and entered widespread service in the Soviet Army in the early 1950s. Its firepower, ease of use, low production costs, and reliability were perfectly suited for the Soviet Army's new mobile warfare doctrines. More AK-type weapons have been produced than all other assault rifles combined. In 1974, the Soviets began replacing their AK-47 and AKM rifles with a newer design, the AK-74, which uses 5.45×39mm ammunition.