The trio -- Defense Secretary Jim Mattis, White House Chief of Staff John Kelly and National Security Adviser HR McMaster -- have spent the summer cleaning up crises of Trump's own making, and trying to prevent the North Korean nuclear standoff spinning out of control.
The growing influence of the men Trump likes to call "my generals" has reassured some allies and political opponents, while others are raising eyebrows over military men being in typically civilian jobs.
"There certainly has been a feeling among many of my colleagues that they are a steadying hand on the rudder and provide a sense of consistency and rationality in an otherwise zig-zagging White House," Democratic Senator Richard Blumenthal told The Washington Post.
The generals' spit-and-polish gravitas was at the fore when Kelly, a recently retired Marine four-star who served in the Gulf War and the Iraq War, was promoted to Trump's chief of staff in July.
Kelly, who had been heading the Department of Homeland Security and took over from Republican figurehead Reince Preibus, moved quickly to impose order.
He booted the president's brash spokesman Anthony Scaramucci -- far-right chief strategist Steve Bannon left shortly after -- and Kelly reportedly has curtailed who sees Trump, including daughter Ivanka.
But Kelly is unable to keep his boss entirely on message, as displayed during the disastrous press conference last month where Trump defended white supremacists after deadly violence in Charlottesville, Virginia.
The generals "cannot control everything that comes out of his mouth, but they can slow things down, they can moderate his instincts," said Eliot Cohen, a professor at Johns Hopkins School of Advanced International Studies, who knows Mattis, McMaster and Kelly.
"They can try to get a much more deliberative process than you would have had if somebody else was in charge," he said.
Trump's martial fascination dates back to his youth, when his father sent him to a private military academy in New York, where students wore uniforms and were given ranks.
He got five deferments from being drafted during the Vietnam War, but Trump has a reverence for the military and repeatedly pledged "historic" increases in defense spending.
Cohen said Trump has "fantasies about what military people are like" because "he's a tough guy and they're tough guys."
Trump also hired Michael Flynn, a retired army three-star general, as his first national security adviser but he was soon fired for his undisclosed Russia contacts.
Another three-star, retired Army lieutenant general Keith Kellogg, has been appointed to head up the National Security Council.
Jonathan Stevenson, a senior fellow at the International Institute for Strategic Studies, said military folk aren't necessarily best suited for civilian jobs.
"The generals are geared towards operational decisions and activity, and usually lack the vision and foresight required to formulate grand strategy and shape the country's direction," Stevenson told AFP.
But he added that by serving Trump, the generals risk compromising their hard-wired military values.
He pointed to McMaster's attempts to exculpate Trump after it emerged he had divulged sensitive Israel-sourced intelligence to Russian officials, and his support for a new Afghanistan plan that Stevenson called "half-baked."
"For all that, there is some hope that the generals will rein in Trump sufficiently to avoid a tragic war on the Korean Peninsula," Stevenson said.
McMaster is an active-duty Army lieutenant general who wrote "Dereliction of Duty," a book about leadership failures in the Vietnam War.
When Pyongyang blasted a ballistic missile over Japan last month, Trump warned that military options were on the table and insisted negotiations were "not the answer."
Mattis quickly dialed the message back, saying the United States was never out of diplomatic avenues in the long-running crisis.
A lifelong scholar known for quoting historical figures including Athenian general Thucydides, Mattis is in many ways the opposite of Trump, who has said he reads little.
The US press has made much of the apparent divergence, but Mattis insists the men are on the same page.
"If I say six and the president says half a dozen, they're going to say I disagree with him," Mattis told reporters. "So let's just get over that."
Stevenson said Mattis is key in Trump's administration as he "is a generally sensible man who commands enormous respect from rank-and-file soldiers to senior officials."
Some observers however are raising concerns about whether military-minded people are growing too prominent.
Retired lieutenant general David Barno and Nora Bensahel of the School of International Service at American University wrote they were particularly troubled by Kelly's ascension to chief of staff, a partisan political role.
"By elevating a recently retired general to what is arguably the second most powerful position in the West Wing, the influence of military men in senior administration jobs is no longer confined to the realm of national security," they said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)