Hungary–Romania relations
During World War II, Hungary and Romania became allies and participated in the war against the Soviet Union. But after the coup on 23 August 1944 Romania switched sides and fought against Hungary. Consequently, Soviet and Romanian troops invaded Hungary, occupied Northern Transylvania by October 1944 and re-established the Romanian administration in the region in March 1945. The 1947 Treaty of Paris reaffirmed the borders between Romania and Hungary as originally defined in Treaty of Trianon 27 years earlier, thus confirming the return of Northern Transylvania to Romania.
World War II by country
Haiti remained neutral in World War II until the bombing of Pearl Harbor. Thus, in late 1941, Haiti declared war on Japan (8 December), Germany (12 December), Italy (12 December), Bulgaria (24 December), Hungary (24 December) and Romania (24 December). Out of these six Axis countries, only Romania reciprocated, declaring war on Haiti on the same day (24 December 1941). Haiti gave food supplies to Allied forces and hosted a detachment of the United States Coast Guard but did not contribute troops, however "five" Haitians from the Haitian Air Force were integrated into the U.S. military (Tuskegee Airmen division) and fought in the war. The President of Haiti, Élie Lescot, introduced several unpopular emergency measures during the war, which critics claimed were designed to increase his power. Lescot was deposed the year after the war ended.