Is ISIS defeated? If not, are U.S. troops in Syria the answer?

President Donald Trump's pronouncement that the Islamic State has been vanquished in Syria and his controversial decision to withdraw U.S. troops from the war-torn nation have raised the question of whether the beleaguered militant group really has been beaten.

"We have defeated ISIS in Syria, my only reason for being there during the Trump Presidency," Trump tweeted Wednesday before ordering the withdrawal of more than 2,000 troops.

"The challenge with taking on a group such as ISIS is it’s like taking a baseball bat to a beehive," Kazianis told USA TODAY. "You can crush the hive – in this case, ISIS and its so-called caliphate. You can kill all the bees – think their soldiers and military equipment. However, there will always be a few bees left that can sting you – that means terror attacks, cyber operations and perhaps even attacks on the U.S. homeland."

"Most people suspect ISIS is transforming into a more traditional terrorist insurgent group now that it has lost its caliphate," Piazza said. "It still has fighters in Iraq and Syria, but they have gone underground."

"If removing U.S. troops introduces more instability into the region, ISIS could exploit that and reconstitute itself," Piazza said. "It begs the question of what our policy toward ISIS currently is. Are we just declaring victory and going home, assuming that ISIS is beaten once and forever?"

British Defense Minister Tobias Ellwood said he believes ISIS is far from conquered. "It has morphed into other forms of extremism and the threat is very much alive," he said.