Timeline of expansion

1949: 12 countries, including the US, the UK, and France, signed the North Atlantic Treaty in Washington, DC, on April 4, establishing NATO.

1955: In response to West Germany's NATO accession, the Soviet Union and seven Central and Eastern European states formed the Warsaw Pact.

1991: NATO started to forge partnerships with former republics of the Soviet Union after its disintegration, and Warsaw Pact ceased to exist.

1999: NATO planes carried out a 78-day bombing on the Federal Republic of Yugoslavia without UN approval. Three Chinese journalists were killed in a strike at the Chinese embassy in Belgrade.

2001: US-led NATO forces invaded Afghanistan, starting a 20-year war against the Taliban, which ended with the full withdrawal of troops in 2021.

2003: Forces led by the US, including NATO members, invaded Iraq, on claims that Iraq possessed weapons of mass destruction and harbored terrorist group al-Qaida, which were later found to be untrue.

2011: NATO intervened in Libya's civil war by setting up a no-fly zone. NATO's intervention resulted in a civil war that continues to this day.

2018: The US, France, and the UK, all NATO member countries, launched missile strikes against Syria, claiming to destroy chemical weapons storage sites and research facilities.

2022: After NATO dismissed Russia's demands to stop eastward expansion, in particular, to Ukraine, the Russia-Ukraine conflict started in February.