Top DHS official on how his background informs his mission: Dismantling drug cartels

Deputy Homeland Security Secretary John Tien, a 24-year Army vet, now finds himself with a new challenge, handed down by Secretary Alejandro Mayorkas specifically because of his background: defeating, disrupting and dismantling Mexican drug cartels.

"These cartels are responsible for human smuggling, human trafficking, narcotics trafficking in particular, who are making, shipping and selling dangerous and deadly narcotics," Tien told ABC News in an interview, laying blame with them for the spread of opioids like fentanyl.

Tien is one of the most senior law enforcement officials in the country. His status as a veteran isn't so unique -- there are about 54,000 others working at the department, or about 20% of employees -- but it informs his work even out of the military.

So, too, does his heritage.

"As a first-generation Asian American, I know that I've got a responsibility to be both seen and heard," he explained. (May is Asian American and Pacific Islander Heritage Month.)

The son of Chinese immigrants, Tien spent his early childhood in Pittsburgh. He learned from his mother "how to be a servant leader" and from his father how to lead a life of public service. That path began with a single conversation in the weight room.

"I really think you should consider West Point, not any of the other military academies, just West Point," Tien recalls his father saying. "And I said, 'Why?' And he said, 'Because you wouldn't be sitting here today, you wouldn't be [an] American citizen, without the United States of America accepting our family, your grandfather's family ... through Ellis Island.'"

Tien followed his father's advice, attending the U.S. Military Academy, where he became the first Asian American to serve as the first captain and brigade commander, the school's top-ranked cadet position.

He ultimately served three tours in Iraq -- with his first being Operation Desert Storm -- then went on to both private sector and government work.

Decades later, Tien said his motto while at the academy -- "duty, honor, country" -- and the motto of the Department of Homeland Security are "essentially one and the same."

"That motto literally is in my DNA. It's my life credo," he said. "And it has indeed been the throughline of my life and how I aspire to act and behave."

When Mayorkas called him about a job in 2021, Mayorkas told him he has "the right combination of experience and skills at the right time for the nation," said Tien, who previously worked on the National Security Council in the Bush and Obama White Houses.

"The way al-Qaida operates is very similar to the way the cartels operate," he said.