When North Korea invaded South Korea in June 1950, the U.S. military announced it would not provide beer rations for the men fighting the war in Korea.

When WW II broke out, and the U.S. government saw beer as what we would today call a "force multiplier." It declared beer production an essential wartime industry, with 15% of its output reserved for the military.

A U.S. representative, Democrat Andrew J. Biemiller, who represented Milwaukee, demanded on the House floor that the Army explain its rationale for cutting off its soldiers' taps. He argued that beer could be used in place of water when necessary and had "as much alcohol as a good pudding."

While the war raged in Korea, the war at home between beer lovers and anti-alcohol groups like the Woman's Christian Temperance Union was fought to keep beer out of the hands of the GIs. Then, a couple of brewing heavyweights escalated the conflict.

Milwaukee's own Jos. Schlitz Brewing Company and Blatz Brewing Company offered to buy the troops a round and see what might happen.

 The companies donated 600,000 cans or bottles (apiece) of beer to be sent to the Korean Peninsula and handed out to the Americans fighting there.

It's hard to argue with American companies offering to get 1.2 million beers to a fight without using taxpayer money. The Woman's Christian Temperance Union would have a hard time competing with that offer. Army Secretary Frank Pace agreed to the donation, so long as the beer was less than 3.2% alcohol by volume.

The first cans of Schlitz, which was America's top beer at the time, rolled away from Milwaukee on Sept. 28, 1950. Blatz wasn't far behind, shipping theirs out on Oct. 4, 1950. The beer made it to the troops in time for Christmas.

https://www.military.com/history/when-army-stopped-serving-beer-american-beer-barons-bought-round-freedom.html