U.S. casualties

A week ago, President Obama appeared on national television to declare an end to a combat role for the nearly 50,000 U.S. troops remaining in Iraq.

"Operation Iraqi Freedom," which cost the United States more than 4,000 American lives during seven years of warfare, "is over and the Iraqi people now have lead responsibility for the security of their country," he told the American people.

But it came with a caveat. Although the primary American role would be to train and support Iraqi forces, U.S. forces are still in harm's way and could be pulled into combat. And it did not take long for that to happen.

On Sunday, American troops were drawn into the fight between Iraqi soldiers and seven insurgents, attacking the latter's headquarters in the center of Baghdad.

The insurgents were killed or committed suicide when they detonated explosive belts, but they held off troops with Iraq's 11th army division for nearly three hours. At least 12 people were killed and 36 wounded.

Iraqi troops called for help from American troops, who provided surveillance from helicopters and unmanned drones. According to one witness, U.S. troops fought with two insurgents who managed to enter a building before Iraqi commanders ordered Americans to stop firing.

No Americans were injured then. However, two U.S. soldiers were killed and nine others wounded Tuesday when a gunman opened fire at another army compound, making them the first casualties of Operation New Dawn.

The assault was the latest in a series of attacks indicative of the rising violence in the country.

President Obama called the end of U.S. combat operations a "historic moment." American deaths have dropped sharply as our role as diminished. But the two incidents this week are reminders that the threat to our troops remains regardless of a change in mission or change in name.