If you are talking about the international situation specifically in 1950, then you are definitely talking about one of the epochs of the Cold War. Over the course of 1949, Washington established NATO, the Soviet Union developed the atomic bomb, and China fell to the Communists. It would turn out that Communism was not the monolithic power that Washington feared it was--within a decade, the Sino-Soviet split would begin, but it definitely appeared at the time as if the world really was splitting into two distinct camps (yes, the fact that the Soviet Union supported Israel's creation in 1948 makes that region a little more muddled during this period, but the Israeli-Arab conflict would take on clear sides over the course of the Cold War). This made the invasion of North Korea into South Korea that much more startling to Washington, which viewed the conflict as the spread of the monolithic Communist power into a region controlled by an American ally. The UN authorized military action against North Korea--neither China nor the USSR vetoed this action, because the UN had given "China's" seat on the security council to Taiwan, and because the USSR abstained from UN activity in protest of this decision--and the United States soon found itself in its first proxy war against (what Washington believed to be) further Soviet expansion.

If you were making a game that features the diplomatic perspective of the United States in 1950, I would think that you'd want to focus on the capitalist/communist conflict that was, at the time, posed to descend the world into a third world war (even if it turned out that China and North Korea both had objectives different from those of Moscow and that Communism was not a monolithic power that could swallow the entire earth--we didn't know that in 1950!).