Story highlights Some lawmakers from both parties would like to see Trump seek new authorization for strikes against Syria

Bush invoked the AUMF 18 times. President Barack Obama used it on 19 occasions

(CNN) Three days after the Sept. 11 terrorist attacks, Congress voted to give former President George W. Bush vast executive authority to wage war overseas.

The 2001 Authorization for Use of Military Force, or AUMF, is only one long sentence. But its 60 broadly written words helped pave the way for nearly 16 years of military activity by three successive presidents from both political parties in more than a dozen countries, from Iraq and Afghanistan to Cuba and Somalia.

The Trump administration, like its predecessor, has already used the 2001 AUMF as legal justification for strikes against ISIS. But the rationale for last week's missile attack on the Assad regime is still unclear. Early indications suggest Trump will call on the president's Article II powers under the Constitution to form the core of his basis for action.

According to official documents, Bush invoked the 2001 AUMF 18 times. President Barack Obama used it on 19 occasions. Like Trump, both also frequently cited their constitutional authorities.

On Friday, Arizona Sen. John McCain told BuzzFeed he believed that Trump's actions could be justified under the 2001 AUMF. But Steve Vladeck, a CNN legal analyst and national security law professor, was skeptical. "There's just no (legal) argument that the 2001 AUMF authorizes force against the Assad regime," he said in an interview with CNN's Ariane de Vogue.

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