The time limit has also been extended to 1953 and additional warfare and diplomatic options have been included.A WWIII expansion to critically acclaimed Hearts of Iron II, Hearts of Iron 2: Doomsday includes the original game and improvements requested from the previous titles worldwide audience. This new what if scenario features a continuation war between the United States and the Soviet Union. In addition to the four grand campaigns (1936, 1939, 19) of the original game, one extra scenario (1945) has been added. As both nations attempt to claim superiority, a new war is waiting around the corner this time, the conflict will decide who will be the remaining superpower.

In the West, there is the United States, leader of the allied nations, and in the East lies the Soviet Union under communist rule. As the German war machine falls, two great nations rise to claim power.