KUNDUZ, Afghanistan — Forced to confront the rising insurgency in once peaceful northern Afghanistan, the German Army is engaged in sustained and bloody ground combat for the first time since World War II.

Soldiers near the northern city of Kunduz have had to strike back against an increasingly fierce campaign by Taliban insurgents, while carrying the burden of being among the first units to break the German taboo against military combat abroad that arose after the Nazi era.

At issue are how long opposition in Germany will allow its troops to stay and fight, and whether they will be given leeway from their strict rules of engagement to pursue the kind of counterinsurgency being advocated by American generals. The question now is whether the Americans will ultimately fight one kind of war and their allies another.

For Germans, the realization that their soldiers are now engaged in ground offensives in an open-ended and escalating war requires a fundamental reconsideration of their principles.

After World War II, German society rejected using military power for anything other than self-defense, and pacifism has been a rallying cry for generations, blocking allied requests for any military support beyond humanitarian assistance.

German leaders have chipped away at the proscriptions in recent years, in particular by participating in airstrikes in the Kosovo war. Still, the legacy of the combat ban remains in the form of strict engagement rules and an ingrained shoot-last mentality that is causing significant tensions with the United States in Afghanistan.