The Russian intervention in Crimea in 2014 led to strong condemnation by NATO nations and the creation of a new " spearhead " force of 5,000 troops at bases in Estonia , Lithuania , Latvia , Poland , Romania , and Bulgaria . At the subsequent 2014 Wales summit , the leaders of NATO 's member states formally committed for the first time to spend the equivalent of at least 2 % of their gross domestic products on defence by 2024 , which had previously been only an informal guideline
2014 Wales summit
2014 Wales summit
NATO