North Vietnam invaded Laos

North Vietnam invaded Laos in July 1959 aided by the Pathet Lao and used 30,000 men to build a network of supply and reinforcement routes running through Laos and Cambodia that became known as the Hồ Chí Minh trail. It allowed the North to send manpower and materiel to the Việt Cộng with much less exposure to South Vietnamese forces, achieving a considerable advantage.