Vikram J. Singh served in senior positions at the State Department and Department of Defense before founding Red Cedar Global Strategies in 2018. He is a senior advisor to West Exec Advisors, the U.S.-India Strategic Partnership Forum and the United States Institute of Peace. The views expressed below are his own.

On a recent flight back from New Delhi to Washington, my seatmate was a typical American success story in the making. The young man, who I'll call Ashok, said he was finishing his master's degree at a top 20 engineering school, where he applies artificial intelligence and machine learning to aeronautical engineering.

"So, where to after graduation?" I asked. "Lockheed or Boeing? SpaceX? Some startup?"

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"Oh, I'm not staying in America," Ashok said bluntly. "I'd have to hang around months hoping for an H-1B," the visa for high-skilled workers. "And while waiting, I'm not allowed to work or even leave the country for a vacation. Can you imagine?"

I could not.

For students like Ashok, permanent U.S. residency through a green card would be 10 years away at best. "America doesn't want us to stay," he said. Ashok wasn't mad. He enjoyed graduate school, and it led to job options in Canada, France, Australia, the U.K. and back in India. He's already accepted an offer in Singapore.

Ashok is emblematic of a coming — and self-inflicted — American brain drain. In the 2016 to 2017 and 2017 to 2018 school years, international applications to U.S. undergraduate and graduate programs declined. Graduate applicants from India alone fell 8.8 percent. Meanwhile, Canada saw an increase of international graduate enrollment of 16.4% in 2017. Since 2014, the number of Indian students in Canada has increased a whopping 350%.

The global talent that America does still attract is increasingly looking to succeed elsewhere in part because it keeps getting harder for U.S. firms to hire and keep foreign talent. According to the National Association of Colleges and Employers, fewer than one in four U.S. companies plan to hire foreign workers.

Other nations and foreign companies thrive on talent that either avoids or leaves the United States. In Toronto, I recently met Vikram Rangnekar, who previously worked with LinkedIn in Silicon Valley. He now runs MOV North, an online community that helps connect global software talent with Canadian companies looking to hire. High-skilled tech workers leaving the U.S. for Canada are by far the largest group using MOV North. Many of them are on increasingly restrictive H-1B visas that tie them to a single employer.

"By contrast, Canada offers several paths, including a 'startup visa' and immediate permanent residency," Vikram told me. He and his wife filled in an online form, gathered the paperwork and were granted Canadian residency in a few months from their home in California. The whole family will have Canadian citizenship in just three years. MOV North started as a blog to give friends advice on moving to Canada and turned into an online business creating jobs in Canada instead of the U.S.

Half of the Fortune 500 companies in America were founded by first or second generation immigrants. The Ashoks and Vikrams who are educated in the U.S. or migrate here to work in high tech do not take jobs from others in America. In fact, millions of computer science, engineering and manufacturing jobs in the United States will go unfilled due to a lack of qualified applicants. In high-tech manufacturing alone, Deloitte estimated that up to 2.4 million jobs could go unfilled between 2018 and 2028, costing the economy $2.5 trillion.

Both Ashok and Vikram said guaranteed health care also factored into their decisions to leave the U.S. With two kids, Vikram sees national health care as entrepreneurial rocket fuel more than an issue of rights. "You can run with your idea because an illness or injury will not be catastrophic to your family," he explained. It's also not a cost he has to worry about while growing the business.

Reducing the inflow and retention of immigrant talent will be an historic strategic blunder for the United States at a critical time. From agriculture and construction to science, engineering and medicine, the United States needs immigrants to remain globally competitive.

President Trump claims he wants to fix the immigration system, but his current policies and latest proposals are off the mark. Harsh anti-immigrant rhetoric, a border wall and family separation make the nation unwelcoming and starve businesses of needed workers while failing to prevent the flow of undocumented migrants (which just reached a five-year high). Talent is pushed away with new rules that prevent H-1B visa holders' spouses from working and reduce the ability of these workers to settle in the U.S. permanently. And Mr. Trump's budget calls for cutting investment in science and research when it should be increasing.

To stay on top, America needs comprehensive immigration reform back on the table. Effective reform will include a robust guest-worker program and innovations like entrepreneur visas. It also needs to continue America's long tradition of family unification and its openness to asylum seekers and dissidents who face oppression around the world. After all, skilled workers are more likely to stay and weave into the fabric of America if they can have their families with them, including by sponsoring parents and siblings. Future great American talents will arrive as refugees like Einstein, Madeleine Albright and Google co-founder Sergey Brin did in the past.

Without immediate policy changes and serious reform for the 21st century, U.S.-trained immigrants like Ashok will use their talents to build Asia or Canada or other parts of the world. Fewer foreigners will fill American classrooms. More jobs will go unfilled. This trend will be hard to reverse, and will only deprive the United States of many people and skills needed to prevent American decline.