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 U.S. 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 the country's 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.

Driven by necessity, some of the 4,250 German soldiers here, the third-largest number of troops in the NATO contingent, have already come a long way. On Oct. 20, they handed out blankets, volleyballs and flashlights as a goodwill gesture to residents of the village of Yanghareq, about 22 miles northwest of Kunduz. Barely an hour later, insurgents with machine guns and rocket-propelled grenades ambushed other members of the same company. The Germans fought back, killing one of the attackers, before the dust and disorder made it impossible to tell fleeing Taliban from civilians.

“;They shoot at us and we shoot back,”; said Staff Sgt. Erik S., who, according to German military rules, could not be fully identified. “;People are going to fall on both sides. It's as simple as that. It's war.”;

“;The word 'war' is growing louder in society, and the politicians can't keep it secret anymore,”; he added.

Indeed, German politicians have refused to utter the word, trying instead to portray the mission in Afghanistan as a mix of peacekeeping and reconstruction in support of the Afghan government. But their line has grown less tenable as the insurgency has expanded rapidly in the west and north of the country, where Germany leads the regional command and provides a majority of the troops.

The Germans may not have gone to war, but now the war has come to them.

In part, NATO and German officials say, that is evidence of the political astuteness of Taliban and Qaeda leaders, who are aware of the opposition in Germany to the war. They hope to exploit it and force the withdrawal of German soldiers—splintering the NATO alliance in the process—through attacks on German personnel in Afghanistan and through video and audio threats of terrorist attacks on the home front before the German elections last month.

Gen. Stanley McChrystal, the senior U.S. and allied commander in Afghanistan, is pressing NATO allies to contribute more troops to the war effort, even as countries like the Netherlands and Canada have begun discussing plans to pull out. Germany has held out against pleas for additional troops so far.

Ties between Germany and the United States were strained last month over a German-ordered bombing of two hijacked tanker trucks, which killed civilians as well as Taliban. Many Germans, from top politicians down to enlisted men, thought that McChrystal was too swift to condemn the strike before a complete investigation.

Germany's combat troops are caught in the middle. In interviews last week, soldiers from the 3rd Company, Mechanized Infantry Battalion 391, said they were understaffed for the increasingly complex mission here. Two men from the company were killed in June, among 36 German soldiers who have died in the Afghan war.

The soldiers expressed frustration over the second-guessing of the airstrike not only by allies, but also by their own politicians, and over the absence of support back home.

While the intensity of the Taliban insurgency in Afghanistan's south has received most attention, the situation in the Germans' part of the north has deteriorated rapidly. Soldiers said that just a year ago they could patrol in unarmored vehicles. Now there are places where they cannot move even in armored vehicles without an entire company of soldiers.

U.S. officials have argued that an emphasis on reconstruction, peacekeeping and the avoidance of violence may have given the Taliban a foothold to return to the north.

German officers here said they had adjusted their tactics accordingly, often engaging the Taliban in firefights for hours with close air support. In July, 300 German soldiers joined the Afghan army and national police in an operation in Kunduz province that killed more than 20 Taliban and led to the arrests of half a dozen more.

The German newspaper Frankfurter Allgemeine Zeitung called the operation “;a fundamental transition out of the defensive and into the offensive.”;

Germany's military actions are controlled by a parliamentary mandate, which is up for renewal in December. The German contingent has unarmed drones and Tornado fighter jets, which are restricted to reconnaissance and are not allowed to conduct offensive operations.

German soldiers usually stay in Afghanistan for just four months, which can make it difficult to maintain continuity with their Afghan partners. The mandate also caps the number of troops in the country at 4,500.

A NATO official, who spoke on condition of anonymity because he was not authorized to speak publicly on the matter, called the mandate “;a political straitjacket.”;

A company of German paratroopers in the district of Chahar Darreh, where insurgent activity is particularly pronounced, fought off a series of attacks and stayed in the area, patrolling on foot and meeting with local elders for eight days and seven nights.

“;The longer we were out there the better the local population responded to us,”; said Capt. Thomas K., the company's commander. Another company relieved them for three days but then abandoned the position, where intelligence said that a bomb was waiting for the next group of German soldiers.

“;Since we were there, no other company has been back,”; the captain said.