On December 24, 1979, the Soviet Union invaded Afghanistan. This was controversial because before the invasion, the Soviet Union signed a treaty with the Afghan government known as the “Friendship Treaty” in 1978. This agreement provided the Afghan government with economic and military assistance, and allowed the Soviet Union a greater foothold in the country. However, Afghanistan no longer benefited from the treaty after President Nur Muhammad Taraki was overthrown by future-president Mohammed Daoud Khan. The instability of Afghan politics gave opportunity for the Soviet Union to spread their influence and gain control over new territory.