Pressure is mounting on President Barack Obama to take the fight against the Islamic State into Syria, with top Republicans calling for the move on Friday after days of attacks on the militants in Iraq and the beheading of American journalist James Foley this week.
"I don't see how we can defeat ISIS without going into Syria," New York Rep. Peter King, a member of the House Homeland Security Committee, told CNN. "I believe in massive airstrikes.
"This is not about Syria. This is not about Iraq," King added. "It's about our national security. The president has the obligation, if he is serious about going after ISIS, to go into Syria."
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Florida Rep. Ilena Ros-Lehtinen later told CNN that "I believe that the president should do that.
"He should have done it when he first announced it when he said Assad has crossed a red line in the use of chemical weapons," she added, referring to Obama's speech in June 2013 when it was confirmed that Syrian President Bashar al-Assad had used the arsenal against his own people. "In fact, they used chemical weapons twice and still we did not do what we said we would do.
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"It was a mistake for us not to act then," Ros-Lehtinen said. "We cannot let this cancer grow."
The GOP House members added to the rising calls for bombing ISIS in Syria after Joint Chiefs of Staff Chairman Gen. Martin Dempsey said that it was critical to defeating the militants.
"This is an organization that has an apocalyptic, end-of-days strategic vision and which will eventually have to be defeated," Dempsey said at a news briefing on Thursday with Defense Secretary Chuck Hagel. "Can they be defeated without addressing that part of their organization which resides in Syria? The answer is no."
The White House signaled on Friday that taking the fight against ISIS into Syria is an option, as Obama nears the end of his two-week vacation on Martha's Vineyard in Massachusetts. The option gained more credence after ISIS posted its video this week showing Foley's brutal execution and threats to kill a second American journalist, Steve Sotloff.
"We will do what's necessary to protect Americans and see that justice is done for what we saw with the barbaric killing of Jim Foley," White House Deputy National Security Adviser Ben Rhodes said on Friday. "So we're actively considering what's going to be necessary to deal with that threat, and we're not going to be restricted by borders."
The U.S. has so far conducted slightly more than 90 airstrikes in Iraq to protect the Iraqi Yazidi religious minority and attack Islamic State positions around the Mosul Dam. Tens of thousands of Yazidis have fled their homelands since ISIS began seizing them last month.
The Pentagon said on Friday that U.S. warplanes made three more airstrikes against Islamic State targets near the Mosul Dam, including a machine gun position that was firing on Iraqi forces.
Extending the fight into Syria, however, would allow opportunities for disrupting the Islamic State's supply lines.
Arizona GOP Sen. John McCain said this week that ISIS fighters have moved military equipment seized in the northern Iraqi city of Mosul into Syria and that they hold enclaves in Syrian territory that have been identified. The heavy artillery was left in Baghdad after the U.S. pulled out of Iraq in 2011.
Florida Sen. Marco Rubio, a prospective 2016 presidential candidate, said on Friday that attacking ISIS supply lines, command and control centers, and economic assets inside Syria was "at the crux of the decision" for Obama.
The risk of "getting sucked into a new war" is outweighed, Rubio said, by the risk of inaction.
A move into Syria, even only with air strikes, would be a reversal for Obama. He stepped back from a threat to launch airstrikes in Syria a year ago in response to a chemical weapons attack by Assad.
Obama has many times rejected greater involvement in the three-year-old Syrian civil war over the past year out of concern about getting entangled in a conflict with no clear positive outcome for the United States.
But officials say the situation now is different because Islamic State militants represent a direct threat to Americans and American interests. Hagel said underscored the importance of preventing ISIS from regrouping — even partly into Syria — and launching renewed attacks.
The Islamic State is also known as ISIL.
"The president, the chairman and I are all very clear-eyed about the challenges ahead," Hagel said. "We are pursuing a long-term strategy against ISIL because ISIL clearly poses a long-term threat. We should expect ISIL to regroup and stage new offenses."
Not going into Syria, essentially, puts the U.S. "back to where you were," said Robert Ford, a former U.S. ambassador to Syria who quit in February in disillusionment over Obama's unwillingness to arm moderate Syrian rebels in their battle against Assad.
"I don't see how you can contain the Islamic State over the medium term if you don't address their base of operations in Syria," he said.
U.S. Special Forces have already had one direct ground battle with Islamic State militants in Syria. That was during the nighttime helicopter mission during the July Fourth Weekend when two dozen Delta Force commandos sought to rescue Foley, Sotloff, and several other Americans.
A number of militants were killed in the firefight, the White House said this week — and one U.S. soldier was wounded. The hostages were not at the location.
More broadly, however, the U.S. strong consideration of going into Syria reflects a more serious approach to ISIS than six months ago, when Obama told New Yorker magazine that they were the "JV team."
The term is short for "junior varsity" — meaning that they are not the best players on the field.
King slammed Obama for the reference in the CNN interview.
"The president was wrong when he called them 'junior varsity.' This was no secret in the intelligence community," he said. "This was no secret — and the president seemed content in saying that al-Qaida was defeated and that, basically, this was all behind us.
"I actually believe that, now, ISIS is more powerful now and more deadly than al-Qaida was on Sept. 11," King said.
The Associated Press and Reuters contributed to this report.
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