combat mission
Noun
Meaning
a mission to capture or defend something
Source: WordNetHypernyms
Examples
Of course, violence will not end with our combat mission. Extremists will continue to set off bombs, attack Iraqi civilians and try to spark sectarian strife. But ultimately, these terrorists will fail to achieve their goals.
Our combat mission is ending, but our commitment to Iraq's future is not.
A full account of Yellin’s war-time experience can be found in the book The Last Fighter Pilot: The True Story of the Final Combat Mission of World War II.