"C. was overthrown by invading Mongol tribes in A.D. 1279" would be the best phrase describing China's Song Dynasty, but this was of course not always the case.
Italy want given the land it was promised by the allies
February 14, 44BC is what I think is the answer.
It meant that as soon as one country falls under communist control, another country would fall and so on. Vietnam at the time was split into North (communist) and South (being attacked by North) and the US didn't want communism to spread, reasoning that it might eventually come to the US if nothing was done.
