The White House says President Obama does not need Congressional approval for expanded strikes against ISIS in Iraq and possibly Syria because he already has the authority he needs based under the 2001 Authorization for Military Force against Al Qaeda and its affiliates that was passed by Congress in the aftermath of the 9/11 attacks.

While ISIS and Al Qaeda were previously affiliated - ISIS is an offshoot of Al Qaeda in Iraq - they officially split earlier this year after disputes over control. And legal experts question whether a measure authorizing force against those who struck the U.S. on 9/11 should be applied in the case of a group that, no matter how bad they may be, ostensibly had nothing to do with the 2001 attacks.

The White House today made clear that, legally speaking, the president considers the two groups to be the same given their past shared history.

"It is the view of this administration that the 2001 AUMF continues to apply to ISIL," Press Secretary Josh Earnest told ABC at the daily briefing.

"There is a long history here that for a decade or more ISIL was actually known as al-Qaeda in Iraq, and that there was important coordination and communication that was taking place between the leaders of al-Qaeda in Iraq and the al-Qaeda leadership, including Osama bin Laden," he said. "That long - decade-long or more - relationship is not something that can be disregarded as the result of one internal disagreement that was aired in public."

Earnest went on to note that there are continued ties between the two groups and that ISIS carries out the same brutal tactics employed under their previous name, citing the recent killings of Americans James Foley and Steven Sotloff.

"The tactics of al-Qaeda in Iraq have not changed simply because they've changed their name," Earnest said.

House Speaker John Boehner said earlier today that a vote to authorize force would "be in the nation's interest" - and Congress', too - but that the White House should draft the language.

"I believe it's in the institution of the Congress' interest to speak on this question," Boehner told reporters. "Now, normally in such a case, I've been through this a few times over the 24 years that I've been here, the president of the United States would request that support and would supply the wording of a resolution to authorize this force. And, at this point in time, we've not gotten that request and we've not seen that language."

The president said last night he would "welcome congressional support" but that he doesn't need lawmakers approval. "I have the authority to address the threat from ISIL, but I believe we are strongest as a nation when the president and Congress work together," he said.

To further complicate matters, a year ago the president called for the repeal of the 2001 Authorization for Use of Military Force.

"I intend to engage Congress about the existing Authorization to Use Military Force, or AUMF, to determine how we can continue to fight terrorism without keeping America on a perpetual wartime footing," Obama said in a speech at the National Defense University in May 2013. "Unless we discipline our thinking, our definitions, our actions, we may be drawn into more wars we don't need to fight, or continue to grant Presidents unbound powers more suited for traditional armed conflicts between nation states."

"I look forward to engaging Congress and the American people in efforts to refine, and ultimately repeal, the AUMF's mandate. And I will not sign laws designed to expand this mandate further. Our systematic effort to dismantle terrorist organizations must continue," he said.