Oscar Vazquez, a former illegal immigrant who returned to Mexico and successfully applied to re-enter legally, has joined the Army.

The move can lead him to the front lines as well as to U.S. citizenship.

Vazquez, 24, who graduated from Arizona State University with an engineering degree, had long talked of joining the military. He discussed it last summer as he sat in a tiny duplex apartment in Magdalena de Kino, Mexico, waiting for the government to decide whether he was worthy to live legally in the United States.

Vazquez visited a Phoenix recruiter in January, his wife, Karla Vazquez, said. Even the recruiters were surprised that the newly minted resident wanted to join.

"It was like, 'And the first thing you want to do is join the Army? OK.' " she said.

Upon getting his visa and returning to the United States in August, Oscar looked for an engineering job, his wife said, but found little success. Companies were not hiring, she said.

Frustrated, Oscar decided it was time to enlist. Karla said she always knew her husband would join the armed forces.

"It was just a matter of when," she said.

Oscar joined the ROTC in high school, continuing the training because he loved the discipline and rigor even though he could not join the military because of his legal status.

Vazquez entered the U.S. illegally at age 12. His mother led him through a hole in the border fence near Douglas.

He enjoyed success as a member of a robotics team at Carl Hayden High School in west Phoenix. The four-person team of illegal residents garnered attention for winning an underwater robot competition and defeating several colleges, including the Massachusetts Institute of Technology. That story was featured in Wired magazine and has been optioned for a movie.

Oscar earned a scholarship at ASU, but it was taken away when the Legislature passed a law that barred illegal immigrants from receiving financial aid. He paid for his education by working construction and using money sent to a fund by readers of Wired magazine.

Oscar, realizing his legal status would prevent him from using his degree, returned to Mexico and applied to re-enter legally. His wife, a U.S. citizen, and infant daughter stayed in Phoenix.

Ten days after Oscar's story was featured in The Republic, the government granted his request for a visa. Sen. Dick Durbin, D-Ill., a longtime proponent of immigration reform, read his story and got involved.

Shortly after returning legally to the country, Oscar filed citizenship papers. He is set to take the exam and have his interview this month, his wife said.

When Oscar enlisted, it was as an Army specialist rather than a private, thanks to his degree, Karla said. She said her husband scored in the 90th percentile nationwide in aptitude and physical-fitness entry tests.

She has exchanged dozens of letters with her husband, in which he has described the rigors of basic training.

"He's happy that he did it," Karla said.

Oscar has written that the drill instructor has been "freaking them out," saying that they will all be deployed to war two months after they get out. She's unsure whether her husband will be sent into harm's way.

"I'm nervous about it," she said.

After basic training, Oscar wants to go to Fort Bragg, N.C., in hopes of joining an airborne division. He also wants to pilot Apache helicopters.

Wherever he's stationed, Karla says, she and their daughter will join him.

She will get to see her husband April 15 during his weekend leave.

He will graduate in June, in a ceremony that Karla said would include his swearing-in as a citizen.

Reach the reporter at 602-444-8473 or richard.ruelas@arizonarepublic.com.