Winning in Iraq (Whatever that means) will not cause a victory to the "War on Terror".
It seems improbable that they will win miliotarily in Iraq. After all, there are 22,000,000 Iraqis and the US and thye UK have well under 200,000 troops. The Iraqi military ranges from barely competent to hideously wimpy.
Tet was a psychological victory of the Viet Cong and NVA over the US, if not a military one.
The Iraq War, like the Vietnam War, is a war of an occupying force, which everyone knows, must someday leave, over a native insurgency, which everyone knows, is bound to stay. The US cannot win this militarily. There could be a political solution that is less than a total train wreck for the USW, but they will need better and more flexible diplomats than the clowns Juniorbush has hired.