Analysis by Stephen Collinson, CNN

(CNN) -- President Donald Trump, though often acting as a champion of the military, has at times politicized the sacrifice of those who paid a terrible price in the nation's wars in a way that few of his predecessors would have countenanced.

He clearly reveres America's fighting men and women. He often boasts about their prowess, has surrounded himself with hard charging generals and has vowed to reinvent veterans' health care. But he's also been happy to use the military for his own political ends when it suits him.

The latest episode -- in which Trump falsely claimed Barack Obama didn't call the families of dead soldiers -- is revealing because it shows how Trump lashes out whenever he believes his conduct or character is under attack. It's another case of him citing information that is either incorrect of unverified when he is on the defensive, a trait that often leads him into deeper political trouble.

And it was yet more evidence of his craving to be seen as more admirable and respected than his predecessors.

Yet both Presidents George W. Bush and Obama spent extended time with wounded soldiers and relatives of those killed, often without publicizing their visits. Obama made calls and wrote letters to families of the fallen, former senior administration officials said. Bush also wrote letters expressing condolences.

After initially attacking Obama's record on paying homage to the fallen at a news conference on Monday, Trump tried to walk it back, admitting in a later answer that he did not actually know what Obama had done.

"I don't know what Bush did. I don't know what Obama did ... I believe his policy was somewhat different than my policy," Trump said on Monday. "I can tell you, my policy is I have called every one of them."

At the time he spoke, Trump had not yet sent out letters of condolence nor called relatives of four US soldiers killed in an ISIS ambush in Niger on October 4. The letters went out Monday afternoon, White House press secretary Sarah Sanders said, and by late Tuesday, Trump had spoken to all four families.

Florida Rep. Frederica Wilson, a Democrat, said late Tuesday that Trump told the widow of a US serviceman killed in the ambush in Niger that "he knew what he signed up for ... but when it happens it hurts."

Wilson said she listened to part of the call on speakerphone while riding with the serviceman's widow in a car.

"The President's conversations with the families of American heroes who have made the ultimate sacrifice are private," a White House official told CNN when asked to confirm the remark.

Trump denied Wilson's claim in a Wednesday morning tweet, saying she "totally fabricated" the accusation and said he had proof, though he didn't immediately provide any.

'Toughest' duty

Putting aside the fact that many more soldiers died on the watches of Bush and Obama, with the Iraq and Afghanistan wars raging at a much higher intensity than they have done so far in Trump's presidency, his comments showed a willingness to politicize an issue that both his predecessors considered sacred.

Trump isn't really helping himself, since by raising the actions of those who came before him he distracted attention from his own attempt to express the overbearing responsibility every president feels when confronted with the cost of sending troops to war. He confessed Monday that his "toughest" duty is calling relatives of the fallen.

Trump positioned himself as a spokesman for veterans throughout his campaign, praising their service, pledging to overhaul the beleaguered Department of Veterans Affairs and even holding a fundraiser for veterans when he decided to skip a Republican primary debate.

Early in his presidential tenure, he also won plaudits for his tasteful remembrance of Chief Petty Officer William "Ryan" Owens, a Navy SEAL killed in a controversial Yemen raid, during his address to a joint session of Congress. Carryn, Owens' widow, garnered 2 minutes and 11 seconds of thunderous, sustained applause when Trump acknowledged her.

interview, dragging up the death in Afghanistan of the son of his chief of staff John Kelly, apparently as a tool to deflect political blame.

"I don't know, you could ask Gen. Kelly, did he get a call from Obama? I don't know what Obama's policy was," Trump said.

Kelly, a four-star general when his son was killed in 2010, has rarely referred to his loss in public. Since he declined interview requests, it is not known how he feels about his boss raising his personal agony in the heat of a political fight.

But the comments baffled John McCain, the Republican chairman of the Senate Armed Services Committee.

"I don't know what to think about that. I think that our first objective has to be to honor the service and sacrifice of these young people who have given their lives," the Arizona senator told CNN.

Not the first time

It's not the first time Trump has trampled sensitivities about war dead to make a political point. During the election campaign, Trump refused to take the high road when the parents of a fallen Muslim soldier, Captain Humayun Khan, criticized him from the stage of the Democratic National Convention. Even before that, the President had trashed taboos, saying at the start of his campaign that McCain, who was tortured in Vietnam, was not a war hero because he was captured.

Captain Khan's parents, Khizr and Ghazala, issued a statement Tuesday accusing Trump of a "lack of empathy" and of "selfish and divisive" conduct that undermined the dignity of the presidency.

The President's assault on Obama's conduct on Monday dismayed some former senior military officers.

"POTUS 43 & 44 and first ladies cared deeply, worked tirelessly for the serving, the fallen, and their families. Not politics. Sacred Trust," Martin Dempsey, the former chairman of the Joint Chiefs of Staff wrote on Twitter.

Retired Lt. Gen. Mark Hertling, now a CNN military analyst, said Trump's conduct was not a "good look" for a commander in chief.

"I would put it in the shameful category," Hertling said, adding that many of his peers, both retired and still on active duty felt the same way.

Another CNN military analyst, retired Lt. Col. Rick Francona, said the controversy was a distraction from the key issue of the Niger ambush, saying Trump "owes it to these families to not only contact him but to tell them what happened."

Pattern of controversy

Trump's defenders will argue that critics are once again seizing on a chance to attack him. The President's political career meanwhile has repeatedly shown that remarks that Washington reporters and political elites view as offensive or often not perceived that way by his supporters.

But it's also true that the President has shown a consistent pattern of controversial or off key remarks about the military.

This is the case even though he insists that his main motivation in condemning athletes who take a knee during the National Anthem are dishonoring the sacrifice of America's fallen service personnel.

In August 2016, a veteran presented the then-Republican nominee his Purple Heart medal. Trump said that he had always wanted one and said getting in this way was "much easier" than serving in combat.

Trump was eligible for the draft during the Vietnam War and never enlisted. He obtained multiple student deferments and ultimately received a deferment for a bone spur to avoid being called up.

In a 1998 interview with radio shock jock Howard Stern, both men compared the danger of contracting sexually transmitted diseases to serving in Vietnam.

"It's very, very dangerous out there," Trump said.

"Yes it is, it's your Vietnam," Stern added.

"It's Vietnam," Trump said.

On the campaign trail, Trump did not shy away from using the military as a prop for attacks on his rivals.

In August, 2016, Trump said US generals had been "reduced to rubble" by the leadership of Obama and former secretary of state Hillary Clinton.

And in November 2015, Trump declared "I know more about ISIS than the generals do, believe me."

Such comments, and his continued propensity for drawing the military into his political spats are only fueling complaints by Trump's rivals that he has not fully understood the grave responsibilities of serving as commander in chief.