Women helped in nursing the wounded, constructing underground rooms and tunnels and fighting the enemy. Along the Ho Chi Minh trail, young volunteers kept open 2,195 kms of strategic roads and guarded 2,500 key points. They built six airstrips, neutralised tonnes of thousands of bombs, transported tonnes of thousands of kilograms of cargo, weapons and food and shot down about fifteen planes. Between 1965 and 1975 out of the 17,000 youths who worked on the trail, 70 to 80 per cent were women. One military historian argues that there were 1.5 million women in the regular army, the militia, the local forces and professional teams