Tehran, seeing an opportunity to bedevil America—a bitter foe since the 1979 revolution that brought the Shiite Ayatollah Ruhollah Khomeini to power, and had even armed Saddam in his war with Iran—was running its own proxy armies inside Iraq. Soon the country’s highways were seeded with sophisticated, Iranian-designed IEDs, specially engineered to penetrate the shells of American Humvees.
