The Cold War with Russia has been revived and NATO finds itself unprepared. This is especially painful because one of the last accomplishments of the NATO organization was the standardization of much equipment so all NATO members could easily communicate with each other and share ammunition, fuel and much else. That standardization eroded as NATO countries replaced aging Cold War equipment with new gear. Now NATO is being asked to reinforce its new East European members and is rediscovering the need for standardization. Even more embarrassing is the discovery that the many of the new East European NATO members were often more “NATO compatible” than the original members of West Europe and North America. That was because the East European bought (or were given) enormous quantities of Cold War era weapons and equipment that was NATO standard. This gear was owned by original NATO members that were demobilizing many of the Cold War era forces in 1990s now that the Cold War was over. A lot of the NATO compatibility rules were still in effect but after 1991 no one really bothered with them as new equipment was bought. It just didn’t seem necessary, but now it is as “Original NATO” nations send forces east to train with and reinforce the new NATO members.
All this came as a shock to the original NATO members because when the Cold War ended in 1991 as the Soviet Union collapsed, about half the population of the Soviet Union chose independence from the Russian (later Soviet) empire. The fourteen former Russian imperial possessions that went independent included the three Baltic states (Estonia, Latvia and Lithuania), Belarus, Moldova, Ukraine, Armenia, Azerbaijan, Georgia and the five “stans” of Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan). Poland, the Baltic States and Finland escaped from the empire after World War I but only Finland managed to stay free through World War II. The Baltic States were retaken during World War II and Poland remained nominally independent but was occupied by Russian troops (and took orders from Russia) until 1989. The new NATO members in East Europe had a very different view of Russia, even though it was now smaller (especially in terms of population) than the Soviet Union. The East Europeans knew that many Russians did not accept the loss of empire and it was proving difficult to convince the rest of the world that this was the case.
Poland and the Baltic States managed to join NATO after the Cold War ended in the hope that the mutual defense terms of the NATO alliance would dissuade Russia. Nevertheless all four, plus Finland, have increased their military readiness as Russia becomes more aggressive and are seeking assurances from the West that they will have help against Russia. Many Finns have called for Finland to join NATO, but a large minority has opposed this because of the fear it would anger the Russians. There was a similar division in Ukraine but now more Finns are thinking that NATO membership is preferable to trusting Russia to always behave. Even Sweden, never part of the Russian empire and successfully neutral since the early 19th century is thinking about joining NATO for protection from an increasingly aggressive Russia. The new (or prospective) members are all for NATO standardization as this makes them more capable to keeping the Russians out. Suddenly NATO membership is fashionable once more, as is NATO equipment compatibility.