On 15 May 1959, the People's Army of Vietnam established Group 559; this unit was charged with the logistics of moving the necessities of war from North Vietnam to the South. Its foremost feat was building and maintaining the Ho Chi Minh trail down the eastern spine of Laos. Eventually, this transportation network would power the Vietnamese communists to victory. It would have to survive a relentless air campaign comparable to any interdiction bombing in World War II.
Also in May, the long awaited integration of 1,500 Pathet Lao troops into the national army was scheduled. The U.S. embassy told the Lao government that it would be difficult to gain congressional approval of aid to Laos with communists serving in the army. The Pathet Lao stalled.[46]