 Complete the following phrase:  In 1979 Soviet troops of the 40th Army crossed the border at Termez via a series of pontoons as part of the Soviet Invasion of Afghanistan, en route to Mazar-i-Sharif and Kabul. They later constructed the Friendship Bridge, which officially opened in 1982, however its strategic importance led to it being a target of the Mujahideen insurgency. The Soviet army 