In a move that immediately sparked alarm among national security analysts, President Donald Trump on Wednesday reportedly scrapped a classified Obama-era memo that set detailed restrictions on how and under what circumstances cyberweapons can be used.

"I've got a bad feeling about this."

—Marcy Wheeler, national security journalist

According to the Wall Street Journal—which first reported Trump's move late Wednesday—the rollback was described by one administration official briefed on the decision as an "offensive step" toward loosening constraints on the military's ability to deploy cyberweapons against foreign "adversaries."

One anonymous official told the Journal that Trump's ultra-hawkish national security adviser John Bolton began calling for the elimination of the Obama-era memo shortly after he arrived in the White House in April.

"The Trump administration has faced pressure to show that it is taking seriously national-security cyberthreats—particularly those that intelligence officials say are posed by Moscow," the Journal noted. "Top administration officials are also devising new penalties that would allow stronger responses to state-sponsored hacks of U.S. critical infrastructure... a mounting worry due to Russia's efforts to penetrate American electric utilities."

While the precise implications of Trump's move are unclear, analysts called the rule reversal a "huge deal" and expressed concern about what lax restrictions on cyberweapon use could mean under Trump's direction.

"I've got a bad feeling about this," independent national security journalist Marcy Wheeler wrote on Twitter.

I've got a bad feeling about this. https://t.co/LCH4Ygv5DM — emptywheel (@emptywheel) August 16, 2018

Officially titled Presidential Policy Directive 20 (pdf), the secret Obama-era memo Trump reportedly reversed on Wednesday was made public in 2013 by National Security Agency (NSA) whistleblower Edward Snowden.

As the Journal reported, the measure "mapped out an elaborate interagency process that must be followed before U.S. use of cyberattacks."

White House officials told the Journal that Trump has replaced Obama's directive with his own rules, but they refused to provide any details.