This is not the same. Imagine a different situation: in 1950 USA gives Florida to Mexico. In 2010s as a result of political transformation, Mexico wants to leave trade agreements with USA and join economic and military alliance led by China, opening possibility for Chinese military base in Miami. Would USA invade in this case?

Based on what we know from the history, yes, USA could do it, as they did in the Bay of Pigs. In fact, USA invaded with military forces in Latin America so many times that by now they should have lost any credibility in democratic world.

Should the US make the previously annexed Hawaii free and let it become The Hawaiian Kingdom again?