You should check a recent map or almanac if you are in doubt. When making reference to a strait, do not use the plural case. Communism is generally not capitalized, though some see it as a religion or like a religion and therefore believe it should be. Communist Bloc, Communist Party, Western Bloc, and Third World should be capitalized. The hyphen is used to put words together.
Hyphenated words are words that are formed from two words.
A general rule is that you will make a mistake using a hyphen more often than the other way around. The only way to be sure is to check the dictionary. Others should be spelled out before a shortened form is used with the short form in parentheses following. If the initials stand for a foreign term spell it out in that language and include a translation. Use only three.