As I said in my last post, it's not so much abandonment, as an amusing "debtor" attitude -- America had to call in favours from France and Spain to get away from Britain, and before the century was out, the Americans were eating up Spanish territory, going to naval war with France, and killing every Indian in sight. In the next century, it begrudged France its aide, and once the war was over, it seemed to take the attitude of "debts repaid, we can forget about the French now."
About the communism bit -- I'm a progressive socialist, and on the payroll of the Labour Party, former the Labour government. My once great nation is still the greatest nation on Earth, and I might point out that, if you're referring to this American fearmongering myth of "the Islamification of Brittanistan", you ought check some figures.
The UK's demographics show that about 2 to 2.5% of Britain is Muslim -- a country of 65 million people, which comes out to, at most, 1.6 million Muslims. In comparison, there are 6.6 million Jews in the United States -- almost five times as many. Furthermore, of those 1.6 million Muslims, over 2/3 claim that they value their "Britishness" over whatever country they came from, in several polls taken by the government. More than that, there are (and this is shocking, I know, if you watch FOX News) no more than 500 (not 5000, not 50000, not 500000) burqa-wearing Muslim women in the entirety of the country. In France, there are 673. In Germany, far less. Furthermore, about a thousand people total claim to follow Shari'a law in Britain, with the vast majority of Muslims in the UK saying that it is "outdated".
How many of the roadsigns in Texas are in Spanish, by the way?