Forward Guidance.

$1.7 trillion of firepower.

1. As Western forces exit Afghanistan, Iran is watching with alarm. The resolution of one long-standing aim, the withdrawal of U.S. troops, is unleashing a separate challenge: what to do about the Taliban, another longtime problem for Iran, swiftly regaining power and territory next door. Iran, ruled by Shiite clerics, and the Taliban, a radical Sunni m…