The French Foreign Legion is an elite corps of the French Army created to allow foreign nationals into French service. The Legion was founded in 1831 and today consists of several specialties, namely infantry, cavalry, engineers, and airborne troops. It formed part of the Armée d’Afrique, French Army units associated with France's colonial project in North Africa, until the end of the Algerian War in 1962.
The Armed Forces of the Russian Federation, commonly referred to as the Russian Armed Forces, are the military of Russia. They are organized into three service branches—the Ground Forces, Navy, and Aerospace Forces—two independent combat arms, and the Special Operations Forces Command.
Naturalization is the legal act or process by which a non-national of a country acquires the nationality of that country after birth. The definition of naturalization by the International Organization for Migration of the United Nations excludes citizenship that is automatically acquired or is acquired by declaration. Naturalization usually involves an application or a motion and approval by legal authorities. The rules of naturalization vary from country to country but typically include a promise to obey and uphold that country's laws and taking and subscribing to an oath of allegiance, and may specify other requirements such as a minimum legal residency and adequate knowledge of the national dominant language or culture. To counter multiple citizenship, some countries require that applicants for naturalization renounce any other citizenship that they currently hold, but whether this renunciation actually causes loss of original citizenship, as seen by the host country and by the original country, will depend on the laws of the countries involved. Arguments for increasing naturalization include reducing backlogs in naturalization applications and reshaping the electorate of the country.
Military service is service by an individual or group in an army or other militia, air forces, and naval forces, whether as a chosen job (volunteer) or as a result of an involuntary draft (conscription).
Permanent residency is a person's legal resident status in a country or territory of which such person is not a citizen but where they have the right to reside on a permanent basis. This is usually for a permanent period; a person with such legal status is known as a permanent resident.
Nationality law is the law of a sovereign state, and of each of its jurisdictions, that defines the legal manner in which a national identity is acquired and how it may be lost. In international law, the legal means to acquire nationality and formal membership in a nation are separated from the relationship between a national and the nation, known as citizenship. Some nations domestically use the terms interchangeably, though by the 20th century, nationality had commonly come to mean the status of belonging to a particular nation with no regard to the type of governance which established a relationship between the nation and its people. In law, nationality describes the relationship of a national to the state under international law and citizenship describes the relationship of a citizen within the state under domestic statutes. Different regulatory agencies monitor legal compliance for nationality and citizenship. A person in a country of which he or she is not a national is generally regarded by that country as a foreigner or alien. A person who has no recognised nationality to any jurisdiction is regarded as stateless.
Singapore maintains an active conscription system in accordance with the regulations set by the Government of Singapore, known as National Service (NS). This requires all qualified male Singaporean citizens and second-generation permanent residents to serve a period of active duty military service in the uniformed services.
Korean Augmentation to the United States Army is a branch of the Republic of Korea Army that consists of Korean enlisted personnel who are seconded to the Eighth United States Army (EUSA). KATUSA does not form an individual military unit. Instead, small numbers of KATUSA members are assigned to positions in most of the departments of the Eighth United States Army, filling in for United States Army enlisted soldiers and junior non-commissioned officers. KATUSAs are selected from a pool of qualified volunteers who are subject to mandatory military service for male Korean citizens.
Polish nationality law is based primarily on the principle of jus sanguinis. Children born to at least one Polish parent acquire Polish citizenship irrespective of place of birth. Besides other things, Polish citizenship entitles the person to a Polish passport.
A military reserve force is a military organization whose members (reservists) have military and civilian occupations. They are not normally kept under arms, and their main role is to be available when their military requires additional manpower. Reserve forces are generally considered part of a permanent standing body of armed forces, and allow a nation to reduce its peacetime military expenditures and maintain a force prepared for war. During peacetime, reservists typically serve part-time alongside a civilian job, although most reserve forces have a significant permanent full-time component as well. Reservists may be deployed for weeks or months-long missions during peacetime to support specific operations. During wartime, reservists may be kept in service for months or years at a time, although typically not for as long as active duty soldiers.
Nationality law of Greece is based on the principle of jus sanguinis. Greek citizenship may be acquired by descent or through naturalization. Greek law permits dual citizenship. A Greek national is a citizen of the European Union, and therefore entitled to the same rights as other EU citizens.
The Lodge–Philbin Act was a U.S. federal law, passed on 30 June 1950, which allowed for the recruiting of foreign nationals into a military force fighting under the command of the U.S. Armed Forces. The Act permitted initially up to 2,500 non-resident aliens to enlist. If they successfully served five years with an honorable discharge, they were guaranteed U.S. citizenship.
The recent history of changes in women's roles includes having women in the military. Every country in the world permits the participation of women in the military, in one form or another. In 2018, only two countries conscripted women and men on the same formal conditions: Norway and Sweden. A few other countries have laws conscripting women into their armed forces, however with some difference such as service exemptions, length of service, and more. Some countries do not have conscription, but men and women may serve on a voluntary basis under equal conditions. Alenka Ermenc was the first female head of armed forces in any of the NATO member states, having served as the Chief of the General Staff of the Slovenian Armed Forces between 2018 and 2020.
Multiple citizenship is a person's legal status in which a person is at the same time recognized by more than one country under its nationality and citizenship law as a national or citizen of that country. There is no international convention that determines the nationality or citizenship status of a person, which is consequently determined exclusively under national laws, which often conflict with each other, thus allowing for multiple citizenship situations to arise.
Ukrainian volunteer battalions were militias and paramilitary groups mobilized as a response to the perceived state of weakness and unwillingness of the regular Armed Forces to counter rising separatism in spring 2014. They trace their origins to the "Maidan Self-Defense" militias formed during the Euromaidan in 2013. The earliest of these volunteer units were later formalized into military, special police and paramilitary formations in a response to the Russian military intervention in Ukraine in 2014. Most of the formations were formed or placed under command of the Ministry of Internal Affairs — as "Special Tasks Patrol Police" — and Ministry of Defence — as "Territorial defence battalions". A minority of battalions were independent of state control.
The Rhodesian government actively recruited white personnel from other countries from the mid-1970s until 1980 to address manpower shortages in the Rhodesian Security Forces during the Rhodesian Bush War. It is estimated that between 800 and 2,000 foreign volunteers enlisted. The issue attracted a degree of controversy as Rhodesia was the subject of international sanctions that banned military assistance due to its illegal declaration of independence and the control which the small white minority exerted over the country. The volunteers were often labelled as mercenaries by opponents of the Rhodesian regime, though the Rhodesian government did not regard or pay them as such.
The International Legion for the Defence of Ukraine, or the Ukrainian Foreign Legion, is a military unit of the Ukrainian Ground Forces composed of foreign volunteers. It was created on 27 February 2022 by the Ukrainian government at the request of President Volodymyr Zelenskyy to fight against the Russian invasion of the country. It was originally part of the Territorial Defense Forces, under the name of International Legion of Territorial Defence of Ukraine, eventually transitioning to the command of the Ukrainian Ground Forces at some point in its existence.
The Russo-Ukrainian War has seen foreign volunteers participate on both sides of the conflict. Most foreign fighters joined the conflict during one of two waves. The first wave happened from 2014 to 2019 during the War in the Donbas and consisted of approximately 17,241 foreign fighters. The second wave is considered by researchers to have been much larger and began in 2022 after the Russian invasion of Ukraine.
Australia 
