Why hasn't Austria joined NATO?
Taking a look upon Europe map highlighting NATO members, I saw a rather strange hole in the center:
Both Switzerland and Austria are the only Central European countries that are not NATO members. Switzerland has a long tradition of neutrality (more than 200 years) and this can be a strong argument from not joining NATO.
On the hand, Austria was involved in both World Wars (as Austro-Hungarian Empire in WW1) and, theoretically, it is placed closer to Russia than Spain or France.
Question: Why is Austria virtually the single Central European country that has not joined NATO?
@DrunkCynic - yes, I found something related to Austrian State Treaty from 1955. However, USSR has fallen for some time and the context is different now (NATO has expanded a lot after 1991 and now includes several ex-communist countries).
@Alexei If you're looking for reading, there's also the converse question of why Austria joining the EU in 1995 didn't contravene its constitutional policy of neutrality.
That addresses the State Treaty of 1955, but there is also a constitutional federal statue of the same year https://www.jstor.org/stable/pdf/2194959.pdf, as well as the Moscow Memorandum, which specifically describes a status of "permanent neutrality" on the Swiss model.
Austria has very deep feelings for neutrality. You can't be neutral if you join NATO. Its like joining a gang in prison: at some point the other members may expect you to shank somebody for them. But since you were literally Hitler just 50 years ago you feel like you had more than your fair share of shanking and would like focus on other things instead.
Does Austria need to join the NATO to get the benefits of NATO membership? If anyone wanted to invade Austria on land, they would have to invade the neighbors of Austria first. I don't know whether it's coincidence or the result of a purposeful action, but Austria enjoys the benefits of the NATO (protection from Russia) without paying the costs.
Short answer: it is not allowed to join NATO.
By the end of WW2 Austria and Germany were occupied by the Allies. In 1955 Austria signed a treaty with the Allies, which - in essence - ended Allied occupation in return for a declaration of perpetual neutrality. This is the reason why there are foreign military bases in Germany (e.g. Ramstein Air Base of the US Air Force), but there are none in Austria, as the Allies left in 1955. Part of the commitment to perpetual neutrality is the ban on joining military alliances, such as NATO.
It should be stated, that it is part of a variety of NATO cooperations. It also participates in a lot of UN missions.
While this is technically correct, the "Moskauer Memorandum" you are referring to was an agreement and not a treaty - it is not legally binding (German Wikipedia has more details than the English one). Since Austria joined the EU, its neutrality has been severly constrained. There has been much discussion in Austria about giving up neutrality and joining NATO but the **actual reason** is that neutrality is part of the Austrian culture and the majority of Austrians wants to stay (officially) neutral.