By The Kansas City Star Editorial Board

There’s jubilation in the streets of Iraq this week as U.S. forces turn over control of the cities to Iraqi forces.

Iraqis see the move as a step toward full independence. American efforts that made this milestone possible should not be underestimated.

But while there is room for optimism, a Mission Accomplished banner isn’t appropriate just yet.

Iraq is much safer today than it was between 2003 and the middle of 2008. But even now, Iraqis face intense dangers. Consider the bombing in Kirkuk Tuesday, in which at least 27 died. Or bombings in Baghdad last week that killed more than 70 citizens.

Iraqi troops should be in charge in Iraqi cities. But U.S. forces are still vital to that nation’s security. While Iraq has developed the ability to man the front lines in the fight against international terrorists and domestic insurgents, it is not yet ready to adequately support those on the front lines. That job falls to American troops.

As U.S. troop numbers fall in Iraq, others must step up, including Iraqi politicians more willing to compromise, supportive neighboring countries, allies willing to provide training and investments, and ordinary Iraqis working together to rebuild safe neighborhoods.

The United States must be strategic with its remaining forces; an expanded Kirkuk Air Base could be used as an international military training ground, as well as a provider of air cover for a nation that lacks its own resources.

U.S. citizens should rejoice with Iraqis at this time. But we should also recognize this celebration for what it is — one in a long flight of steps.