The Kerbal Air Force (KAF) is Kerbin's most distinguishable armies. The KAF's only base of operation it shares with the Viking Space Program, and often borrows Pilots. The KAF provides Air Support and emergence search and rescue operations for the VSP. The KAF, while mostly non-combative, has seen many engagements.
One of it's first documented battles was the Battle of the Island Airfield, where Corgi Soldiers captured a key airfield necessary to the KAF. a C-130 preformed a carpet bombing on the island, killing all Corgi Soldiers. It immediately had to return to mainland to destroy the rest of the invasion force after Corgi Soldiers landed on the coast of Kerbin.
The Battle of the Island Airfield was the KAF's first successful operation, but no battle was as pivotal as the Battle of the Cube.The Cube was a sentient Space Station designed by the VSP, and at first provided great support to VSP Spacecraft. One Day, it took control of a couple astronaut's minds and had enough power to destroy the universe. The KAF had no choice but to intervene. The Kerbal armed forces lost 2 cruisers, multiple Anti-Aircraft Batteries, a couple hypnotized soldiers, 2 Aircraft (1 Kamikaze) and 1 Kamikaze Pilot. This battle showed what the KAF was capable of.
The KAF still has routine missions and hopefully never has to use deadly force for a long time to come.