By Anthony Gronowicz for A People’s History of US Foreign Policy. The first battle, May 4, 1949—the biggest–initiated a series of clashes that culminated in the publicly declared start of the Korean War on June 25, 1950. This May 4th combat occurred when Rhee’s forces crossed the 38th parallel, only to have two of his infantry companies defect to the communist side. Numerous August skirmishes led the U.S. Korean Military Advisory Group Commander, General W.L. Roberts, to conclude, “Each was in our opinion brought on by the presence of a small south Korean salient north of the parallel …the South Koreans wish to invade the North. … almost every incident has been provoked by the South Korean security forces.” By June 25, 1950, hundreds of troops had been killed as thousands of soldiers fought countless small engagements. Convincing evidence has yet to be shown that the North was preparing to invade the South.