True and another difference is that Vietnam is not less than 90 miles from the US and is not busily engaged in promoting communism and anti-Americanism throughout Latin America.  Also, I suppose that American strategists realize the value of relatively strong and prosperous Asian nations as a counterweight to the Chinese colossus.  Unlike Little Potato, you see, the Americans don't admire the Chinese dictatorship (and with Trump will stand up to it more than in recent years.)