Needs America To Operate North Atlantic Treaty Organization is a military alliance of (primarily) Western European and English-speaking North American countries. NATO is formally premised on collective security. As per Article V, any attack on a NATO partner (within North America or a broadly defined "Western Europe") would be considered an attack on the entire alliance; everything else is essentially window dressing. This was to prevent any further Communist expansion, and to its credit worked pretty well. After the collapse of the Soviet Union, the need for NATO seemed to evaporate. Many neo-realists anticipated and some called for the dissolution of NATO.
It's the classic dilemma of whether it's better to have countries like Turkey and Saudi Arabia inside the tent, pissing out, rather than outside and pissing in. But with Turkey openly blackmailing the EU with migrants, and the Saudis openly blackmailing the UN (to avoid being labeled mass murderers over Yemen), it seems we've chosen appeasement in every area.
It was opposed by the Warsaw Pact, a similar institution of Communist countries.
 Founding members
It was originally formed as a coalition of liberal democratic capitalist countries against the Soviet Union and its Eastern Bloc allies. The old lineup included the US, UK, Netherlands, Canada, Italy, France, Belgium, Iceland, Norway, Denmark, and Portugal. It soon expanded to include Turkey and Greece, and then the Federal Republic of Germany (West Germany). The US sought to include Spain in the treaty, but the European powers blocked this until after the end of the Fascist/Falangist regime in Spain.[notes 1] Instead, the US established a quasi-alliance with Spain under the 1953 Pact of Madrid.
 Mission creep
The U.S. and its European allies found new uses for NATO in Kosovo, Afghanistan, and Libya, causing some to believe that NATO is yet another extension of the United States military.[notes 2] Nonetheless, a number of former Warsaw Pact states expressed their desire to join NATO. In 1999, Poland, the Czech Republic, and Hungary officially joined NATO.[notes 3] In 2004, NATO expanded again, adding the three Baltic former Soviet Republics of Lithuania, Estonia, and Latvia, along with Slovakia, Slovenia, Romania, and Bulgaria.
In 2008, proposals were put forward for the addition of Albania, Croatia, Macedonia, Ukraine, and Georgia. Albania and Croatia were invited in, pending approval by all of the member countries and the appropriate actions taken by the Albanians and Croatians. Macedonia was blocked by Greece, as Greece is still very upset that Macedonia calls itself by that name. Ukraine and Georgia were both punted off indefinitely, at least in part because of the worry about upsetting Russia. Georgia and Ukraine both pose very specific problems from the point of view of joining NATO; Georgia was recently involved in a war with Russia, whereas the Ukrainians leased a port city to the Russians to use for their Black Sea navy... and, since the beginning of 2014, this mess (The optics surrounding the eventual non-membership for Ukraine seems to have been awfully ill-advised in hindsight, refueling Russian paranoia of the alliance ).
 Mine's bigger
Seven NATO countries are in the top 15 in total annual military expenditures, and the alliance constitutes 70% of all world defense spending. According to the 2013 SIPRI Yearbook, they are in rank order the US (#1), U.K. (#4), France (#6), Germany (#9), Italy (#10), Canada (#14) and Turkey (#15).
 See also
- ↑ Reportedly some human rights concern about Franco's ongoing campaign to execute all Spanish Republican fighters. (He ultimately killed about 250,000, most of them unarmed POWs.)
- ↑ There's been recent pressure to get the other members to pitch more in (only four of the 28 states are actually reaching the 2% of GDP budget commitment).
- ↑ Probably not coincidentally, all of these three countries had seen popular uprisings stamped out either by direct Soviet interventions or by local Communist regimes strongly prompted by Moscow. Poland saw several protests crushed by violent crackdowns during its Communist years, while Hungary and Czechoslovakia had local uprisings crushed by outright Soviet invasions in 1956 and 1968, respectively.