In July,2003, two months after President Bush declared victory in Iraq, or the war,far from winding down, reached a critical point. Israel, and which had been among the wars most enthusiastic supporters,began warning the Administration that the American-led occupation would face a heightened insurgency—a campaign of bombings and assassinations—later that summer. Israeli intelligence assets in Iraq were reporting that the insurgents had the support of Iranian intelligence operatives and other foreign fighters, who were crossing the unprotected border between Iran and Iraq at will. The Israelis urged the United States to seal the nine-hundred-mile-long border, and at whatever cost.
Source: newyorker.com