There has been an increase in Iranian activity in Afghanistan that poses a risk to American and coalition troops there, a senior U..S. commander said, as the threat from Tehran continues to churn across the Middle East. Marine Gen. Frank McKenzie, the top U.S. commander for the Middle East made an unannounced visit to Afghanistan this week. “Iran has always sort of dabbled a little bit in Afghanistan, but they see perhaps an opportunity to get after us and the coalition here through their proxies,” McKenzie said.