They stand still for an hour on the parade grounds at the Defense Ministry in Berlin, their uniforms fastidiously straightened, their faces concentrated - the 430 recruits whose public vow is something of a history lesson. The young men and women have just joined the Bundeswehr, the German army, having volunteered for service on July 1.

Three weeks later, they participate in a very special day: solemnly they will swear their oaths in front of TV cameras, German Defense Minister Ursula von der Leyen, and 2,000 invited guests.

A military band plays, a guard battalion marches, and an honored guest addresses the young men and women, warning them to preserve the legacy of July 20, 1944 - the date that Claus von Stauffenberg's plot to murder Adolf Hitler at the "Wolf's Lair" headquarters failed.

After that they vow, in unison, to "faithfully serve the Federal Republic of Germany and bravely defend the justice and freedom of the German people." As they do so, six of them lay their hands on the German flag in the name of all recruits.

Remembering the men of July 20

Von Kleist is one of the few surviving plotters

The parade ground at the Bendlerblock hosts this ceremonial vow every July 20, in honor of the officers who tried - and failed - to topple Hitler's regime. Stauffenberg and some of his coconspirators were summarily executed only a stone's throw from the spot where the soldiers make their oath. Today, the road that leads to Defense Ministry is named after him.

Stauffenberg's son Berthold was 10 years old at the time of his father's execution. He and his siblings also had to pay for Stauffenberg's actions - they were separated from their mother and made to live in a children's home. Berthold Schenk Graf von Stauffenberg, who became a Bundeswehr officer himself later, saw his father and the other men of July 20, 1944, vilified as traitors long after the war.

It was only in 1954 that President Theodor Heuss rehabilitated the legacy of the Bundeswehr's resistance against Hitler. "Some acts of insubordination have historical importance," he said in an epoch speech that the government printed and distributed millions of copies of.

The newly-founded German army of 1955 picked up the tradition of those soldiers who put their conscience above their military obedience. "Their spirit and their attitude is our model," the first chief of the new German military, Adolf Heusinger, wrote in 1959 in a call to his commanders.

Limits of obedience

The army's close ties to the constitution and the ideal of "citizens in uniform" have their roots in the military resistance to the Nazi dictatorship. "The actions of a soldier are always tied to the duty to protect the inviolable dignity of every human being," said former Defense Minister Franz Josef Jung at a previous July 20 ceremony. "So orders and obedience have clear boundaries. The men of the military resistance respected these boundaries."

One of these men was Ewald-Heinrich von Kleist, one of the few plotters to escape with his life. At the 2010 ceremony, he talked about the conspirators' motives. He said they had been deeply shamed by the crimes committed in the name of the German people, and had wanted to "end the horrible killing." There had also been the hope, von Kleist said, that it would be possible to tell the world "that not everything had to be accepted."

Peace protesters occasionally disturb proceedings

Von Kleist went on to found the annual Munich Security Conference, which seeks to foster dialogue between the military and the politicians. Today the Bundeswehr is under parliamentary control to such an extent that the oath ceremony takes place in front of the parliament building every other year.

Moving speeches

It's likely some of the speeches stayed in the minds of the young recruits for some time. In 2008, former Chancellor Helmut Schmidt told of how, as a soldier in 1944, he was forced to watch the show trial of the July 20 plotters. It was only then, he said, that he understood the criminal nature of the Nazi regime. And yet he continued to follow his orders, like millions of other soldiers.

"Unfortunately it remains true that we humans are easily deluded," he said. For that reason, it was both morally and politically necessary to learn from history. "This state will not misuse you," Schmidt had told the new recruits.

The first foreign guest to speak at the ceremony was Polish President Aleksander Kwasniewski, who appeared in 2002. The sight of a German military uniform still causes unease in Poland - but Kwasniewski paid tribute to the "peace bringing" Bundeswehr that builds on the legacy of the resistance, which had shown "true patriotism and courage."

Not entirely public

Although the ceremony is broadcast live on TV, only invited guests appear on the stage: relatives, politicians, and soldiers. Because of protests in the past - such as by the anti-military movement Gelöbnix - the surrounding streets are cordoned off.

In 2001, two demonstrators got into the ceremony with the help of a hired limousine, by pretending they were the daughters of then-Defense Minister Rudolf Scharping.