Two American values collided in Sgt. Bowe Bergdahl’s calamity. One had to give.

The one about never leaving a man behind prevailed.

The one about never negotiating with terrorists got lost in the swirling dust storm of a U.S. helicopter retrieving the soldier from his Taliban captors in a swap now provoking recriminations in Washington.

Each ethos runs deep in the American conscience, yet has been violated through history, notably in the age of terrorism, where traditional standards of warfare, spying and negotiating are run through a hall of mirrors.

Bergdahl and the five Guantanamo detainees traded for his freedom were captives in an undeclared, unconventional and open-ended war that never fit neatly into the Geneva Conventions, U.S. military doctrine or slogans about how to behave. Whatever universal rights are affirmed by the old standards, they came from an era of recognizable battlefields and POW camps, with victories and defeats signed with flourishes of a pen.

THE SOLDIER’S CREED

History is replete with extraordinary acts to bring home the lost and fallen.

The U.S. Army’s Warrior Ethos and the Soldier’s Creed both swear, “I will never leave a fallen comrade,” and all the services place a premium on returning the missing, captured and dead. Often this comes at great cost, as in the 1993 Black Hawk Down battle in Somalia in which 18 U.S. servicemen were killed in the attack on U.S. helicopters and the subsequent rescue attempt.

President Barack Obama said the ethos is a “sacred” undertaking that applies to all in uniform without regard to rank or circumstance or, in Bergdahl’s case, his questionable loyalty to the Army. “We have a basic principle,” Obama said Thursday. “We do not leave anybody wearing the American uniform behind.”

As Pentagon spokesman Rear Adm. John F. Kirby put it: “When you’re in the Navy, and you go overboard, it doesn’t matter if you were pushed, fell or jumped. We’re going to turn the ship around and pick you up.”

Not always.

The debate over Bergdahl is roiling as world leaders and ordinary citizens commemorate the 70th anniversary of D-Day. The legions storming the beaches of Normandy, France, from the sea and dropping behind German lines from the sky faced snap decisions under withering fire about what to do with the wounded or trapped. Army history tells of wounded paratroopers left behind for the sake of the mission or the survival of their units. Sometimes medics were left behind, too, because they insisted on staying with the injured.

When the Korean War ended in 1953, thousands of missing and dead American soldiers were left behind, as well as POWs, as U.S. forces retreated from North Korea. Not all the missing and dead were returned after the truce and there was strong evidence some POWs were not handed over. Today the Pentagon is still trying to retrieve remains through a process, currently stalled, of paying North Koreans to support field excavations.

The Pentagon agency primarily responsible for survival training for captured troops and for helping them back at home says the mission of bringing them back is “truly and uniquely an indelible part of the American way.”

ANOTHER AMERICAN WAY

Never negotiate with terrorists or hostage-takers? Not quite never.

The Sept. 11 attacks broke open the modern age of asymmetric warfare. Asymmetric dealmaking, diplomacy and national security went hand in hand with that. The old standards and slogans still had meaning but improvisation was required.

Prisoners taken in the fight against terrorism could not be considered prisoners of war in the U.S. government’s estimation because branding them POWs might extend them rights they were not accorded at Guantanamo, never mind the now-discontinued CIA “black sites.”

Ways were found to deal with those who don’t fight by the rules. As in Bergdahl’s case, where the government of Qatar served as go-between, intermediaries are usually involved to maintain a semblance of separation between two sides that aren’t really supposed to be talking to each other.

Just months after the 2001 attacks, the U.S. dropped its straightforward ban on government involvement in ransom to hostage-takers, for example. The new policy created more wiggle room for the U.S. to facilitate ransom payments and to shape negotiations, however indirectly, with captors.

The policy provided cover for the U.S. to try to free terrorist-held missionaries Martin and Gracia Burnham in the Philippines in 2002 but failed to achieve a peaceful transfer: Martin Burnham died in the eventual assault on the captors.

To be sure, unsavory and prohibited deal-making has a long history, too.

Ronald Reagan’s presidency is stained by the Iran-contra scandal, in which Iran, designated a state sponsor of terrorism, was to be secretly sold U.S. arms in exchange for the release of hostages, with proceeds steered illegally to Nicaraguan rebels.

The ethos against granting concessions of any kind to scoundrels gave rise to a patriotic rallying cry a century ago in the time of President Teddy Roosevelt and a Moroccan plunderer who became known as the first terrorist of the 1900s.

After Ahmed ibn-Muhammed Raisuli took Greek-American businessman Ion Perdicaris hostage for money and political influence, the U.S. dispatched warships while Roosevelt’s secretary of state demanded of Morocco’s sultan: “Perdicaris alive or Raisuli dead.”

The effect of that ultimatum was electrifying at home and, days later, Perdicaris was free. But it turned out the U.S. had quietly pressed for Raisuli’s ransom demands to be met, which they were.

The U.S. appeared to be wielding Roosevelt’s big stick.

Actually it spoke softly to a terrorist.

(AP)