Whether President Trump plans to formally do away with the H-1B visa program as he repeatedly pledged to during his campaign for the presidency or whether he simply plans to make hostile overtures and idle threats to the program, the chilling effect is real. Applications for the H-1B visas decreased for the first time in five years according to CNN Money, though the total number of visas that will be distributed, 85,000, is fixed. The issue is one driving a strong divide between the President and Silicon Valley, who are particularly reliant on a strong global workforce for technical jobs.

The Trump administration began to stoke fears regarding the program's future for technology workers earlier this month when Citizenship and Immigration Service issued a memorandum tightening H-1B rules for programmers. No longer are programmers with just a bachelor's degree eligible for the visas automatically — instead, applicants applying for tech jobs will have to provide supplemental materials if they don't have a professional degree.

Today, Trump signed an executive order dubbed "Buy American, Hire American." The exact nature of the order isn't yet clear, and its legality could of course be contested by the judiciary, but it calls for a "review" of the H-1B visa program "with the goal of reforming the program."

"The buy and hire American order I'm about to sign will protect workers and students like you," Trump told a crowd according to CNN at Snap-On Tools , the Wisconsin-based manufacturer to which he travelled today to provide a backdrop as he signs the order. "It's America first, you better believe it. It's time. It's time, right?"

But Silicon Valley CEOs might see the issue with more nuance. “We need more math-based professionals, and it is quite depressing that we can’t go out and get the best and brightest,” Silicon Valley immigration lawyer Martin Lawler told the Chronicle. Still, Lawler expects that demand will remain "so long as Silicon Valley is doing well.”

Previously: H-1B Visa Rule Tightening Stokes Fears In Silicon Valley, But Threat Could Be Empty