Why was the soviet invasion of Afghanistan troubling to the United States

THis is because Afghanistan is a good place for trade and market, invasion or terrorism in afghanistan will lessen and complicate trade in Asia and America.

Afghanistan being in a very strategic position has provided the Soviet the advantage of controlling trades as it is in the juncture between Asia and middle east. This gave better leverage to the Soviet compared to the united states having control of pakistan after WorldWar 2. The soviet influenced has not been good in terms of improving afghan either as it made several internal tribal sect enemies with each other due to oppression and poor economy impacting poorest of the poor families.