WASHINGTON — Secretary of Veterans Affairs Eric K. Shinseki knows adversity.

As a soldier in Vietnam, he was seriously wounded twice, the second time during a second tour of duty when he stepped on a land mine and lost half of his right foot. That should have ended his Army career. Instead, he asked for, and received, a waiver to stay on active duty.

His determination turned blunt force in 2003 when, as Army chief of staff, Shinseki clashed with then-Defense Secretary Donald Rumsfeld over the George W. Bush administration’s Iraq war strategy. Although history would prove Shinseki correct in his assessment, he retired several months later, after 38 years in the Army.

The uniform was put away, but not the soldier.

Now, the first Japanese American to become a four-star general is in a firestorm, facing a president “madder than hell” and an investigation, whose early results are expected next week, that could determine whether his leadership will survive reports that VA employees have been covering up long wait times for medical care.

But Shinseki, 71, has held this job since 2009, longer than any of his predecessors, and doesn’t give up easily.

“His tenacity in the face of adversity is really very strong,” said Richard Halloran, author of “My Name Is Shinseki and I Am a Soldier.”

Some doubt that Shinseki, in spite of a long and distinguished military career, can turn around the VA.

When he told lawmakers last week that he too was “mad as hell” about the wait lists, he came in for ridicule for his low-key, seemingly passive manner.

“If he’s that mad, he needs a better war face,” Derek Bennett, chief of staff of the Iraq and Afghanistan Veterans of America, said on Twitter.

“Your ‘mad as hell’ face looks a lot like your ‘Oh, we’re out of orange juice’ face,” comedian Jon Stewart said.

But that’s Shinseki, those who know him say: a retired general with a master’s degree in English literature who doesn’t pound the table or raise his voice.

“Ric Shinseki doesn’t get ‘mad as hell,’ ” said retired Gen. Barry McCaffrey, who has known him since their days at West Point in the 1960s. “He is determined, focused and wants to factually understand a problem so he can get a sensible solution. He fired 3,000 VA employees last year. He will take action and hold people accountable.”

REQUEST FOR PATIENCE

Shinseki has asked for patience while the VA inspector general investigates reports of excessive wait times and falsification of records at the department’s medical facilities, and he pledged to veterans last week to redouble efforts to “earn your trust.” Twenty-six VA sites are under investigation.

President Obama said last week that Shinseki had “put his heart and soul” into trying to improve veterans’ services. “If he does not think he can do a good job on this and if he thinks he’s let our veterans down, then I’m sure that he is not going to be interested in continuing to serve,” the president added.

While the American Legion and a number of Republican and a few Democratic lawmakers have called for Shinseki’s resignation, those who know him best say he is likely to remain in the job so long as Obama has confidence in him.

Few dispute Shinseki’s devotion to veterans.

As Army chief of staff, Shinseki called every soldier who lost a limb, retired Army Sgt. Maj. Jack L. Tilley said.

“More than once, he has said, ‘I have been carried out of battle twice on the backs of American soldiers. You can imagine my love for them,’ ” said Halloran, Shinseki’s biographer.

His supporters say he faces a daunting task in dealing with the giant VA bureaucracy, the second-largest federal department after Defense, with 1,700 hospitals and clinics handling 85 million appointments a year. “When you have a force of about 300,000 people, on any given day somebody’s messing something up,” Tilley said.

“He’s trying to bring about change,” said Joseph A. Violante, national legislative director for Disabled American Veterans, citing the modernizing of VA’s disability claims processing system as “a transformation that has already reduced the backlog of disability compensation claims by about half in the past year.”

Shinseki has also managed to reduce the number of veterans who are homeless, extend benefits to Agent Orange victims and provide Post-9/11 GI Bill educational benefits to more than 1 million veterans.

But Dan Dellinger, national commander of the 2.4-million-member American Legion, who has called for Shinseki to resign, contends that the VA set an “unattainable” goal to schedule patients within 14 days of desired appointment dates – a deadline that some employees have claimed forced them to deceptively manipulate wait lists.

“Some things are better, but other things are worse,” Dellinger said. “I’m looking at veterans dying every day because of the inefficiencies of the VA.”

NOT HIS FIRST FIRESTORM

Shinseki has been in firestorms before.

Born in 1942 in Hawaii, Shinseki was inspired to join the military by stories of uncles who served in Japanese American units in World War II. After graduating from West Point in 1965, Shinseki went to Vietnam. In a 2012 talk to VA nurses, he recalled his hospital stay in Da Nang in 1970 after tripping a land mine. A nurse told him that he would face possible amputation of the rest of the foot at the ankle.

He said the nurse told him he could try to save his ankle if he rotated it.

The ankle was saved, and the nurse, he said, changed the course of his life.