It's been a long time, but as I recall from memory, the U.S. started supplying them with shoulder-launched Stinger missile systems. Quite effective against arm

It's been a long time, but as I recall from memory, the U.S. started supplying them with shoulder-launched Stinger missile systems. Quite effective against armored helicopters (and, to a lesser extent, low-flying fighter planes). There was considerable concern over whether and where to those systems might travel / be traded / be sold. But it marked a turning point in the conflict.