linguistic:paraphrasing
World War II (1941–1945)

Hungary formally entered World War II as an Axis power on 26 June 1941, declaring war on the Soviet Union after unidentified planes bombed Kassa, Munkács, and Rahó. Hungarian troops fought on the Eastern Front for two years. Despite early success at the Battle of Uman, the government began seeking a secret peace pact with the Allies after the Second Army suffered catastrophic losses at the River Don in January 1943. Learning of the planned defection, German troops occupied Hungary on 19 March 1944 to guarantee Horthy's compliance. In October, as the Soviet front approached, and the government made further efforts to disengage from the war, German troops ousted Horthy and installed a puppet government under Szálasi's fascist Arrow Cross Party. Szálasi pledged all the country's capabilities in service of the German war machine. By October 1944, the Soviets had reached the river Tisza, and despite some losses, succeeded in encircling and besieging Budapest in December.

On 13 February 1945, Budapest surrendered; by April, German troops left the country under Soviet military occupation. 200,000 Hungarians were expelled from Czechoslovakia in exchange for 70,000 Slovaks living in Hungary. 202,000 ethnic Germans were expelled to Germany, and through the 1947 Paris Peace Treaties, Hungary was again reduced to its immediate post-Trianon borders.

The war left Hungary devastated, destroying over 60% of the economy and causing significant loss of life. In addition to the over 600,000 Hungarian Jews killed, as many as 280,000 other Hungarians were raped, murdered and executed or deported for slave labour. After German occupation, Hungary participated in the Holocaust, deporting nearly 440,000 Jews, mainly to Auschwitz. Nearly all of them were murdered. The Horthy government's complicity in the Holocaust remains a point of controversy and contention.