President Barack Obama's strategy in Syria is apparently an evolving process. At the start of his tenure, he promised to end America's wars in the Middle East and to scale back military involvement in the region, but his announcement Monday sending more troops to Syria appears to show he's been all but forced to consider a more direct approach by the rise of the Islamic State group.

The U.S. is currently leading an intense airstrike campaign against the extremist group, also known as ISIS. Aside from funding and training allied forces on the ground, now the president is deploying 250 additional American personnel to the war-torn nation. At the same time, Obama has remained firm in his position that the U.S. should not send ground troops to the front lines in Syria.

Here are some of Obama's statements over the last five years reflecting his evolving policy toward a war that has claimed the lives of hundreds of thousands and displaced nearly half a nation.

Standing With the Syrian People

In 2011, as an uprising grew in Syria, Obama made clear that the U.S. stood alongside opponents of President Bashar Assad's regime. "The Syrian people have showed dignity and courage in their pursuit of justice. ... Will we stand with the Syrian people or their oppressors?" Obama said in front of the United Nations that year. He called on the international body to adopt strong sanctions against Syrian leaders.

Cautiously Supporting Opposition

Throughout 2012, Obama reaffirmed his support for the Syrian rebels, lambasting Assad’s alleged targeting of civilians. While Obama said the U.S. was aiding the training of "moderate forces inside of Syria," he cautioned against entrenching the U.S. in another endless war, noting that it was up to Syrians to set the country's course.

“For us to get entangled in Syria is a serious step, and we have to do so making absolutely certain who we are helping and we’re not putting arms in the hands of folks who could eventually turn them against us or our allies in the region,” the president said.

He also asserted that the use of chemical weapons would be "a red line."

No 'Boots on the Ground'

In 2013, Assad crossed that "red line" Obama referenced one year earlier. 

In August, United Nations inspectors confirmed that Assad’s regime used chemical weapons on the rebel-held town of Ghouta outside Damascus. Some called for Obama to take action; others urged restraint, cautioning against deeper involvement in the war. Obama said he would seek congressional approval for airstrikes, but would maintain limited operations.

"I will not put American boots on the ground in Syria," he said. "I will not pursue an open-ended action like Iraq or Afghanistan. I will not pursue a prolonged air campaign like Libya or Kosovo."

After the Assad regime and Russia agreed to a plan to dispose of chemical weapons, U.S. threats of airstrikes subsided. Many of the forces being supported by the U.S. on the ground viewed it as a betrayal by the president.

Obama Underestimates ISIS' Rise

ISIS burst on the scene with brutal executions and shocking territorial gains in mid-2014. At first, Obama appeared to have underestimated just how great a threat the extremists, who splintered from al Qaeda, would become. He compared the group to a junior varsity basketball team putting on a Lakers uniform.

"That doesn't make them Kobe Bryant," he told the New Yorker in January 2014. Months later, ISIS had overrun some of Iraq's and Syria's major cities. Obama has since admitted early intelligence errors, acknowledging that the administration had underestimated the threat.

Obama Resists Calls for Military Action

By May 2014, ISIS had captured the persistent attention of media, and a takeover of Iraq's second-largest city of Mosul was looming. The group had already captured major cities, including Raqqa in Syria and Fallujah in Iraq. Obama affirmed during a speech at West Point that he took the threat of terrorism seriously, saying it remained "the most direct threat to America at home and abroad." But he also said, "a strategy that involves invading every country that harbors terrorist networks is naive and unsustainable."

The president added that the U.S. would use military action “when our people are threatened, when our livelihood is at stake, or when the security of our allies is in danger.” 

Obama Authorizes Airstrikes

In early August 2014, thousands of Yazidis, a religious minority, were routed from their homes by ISIS and stranded on Mount Sinjar in northern Iraq under the scorching sun. With a humanitarian crisis growing and reports of mass atrocities, Obama authorized airstrikes against ISIS militants marching toward the Iraqi Kurdish capital of Erbil. U.S. airstrikes supported Kurdish fighters who broke the siege of Sinjar and freed the trapped Yazidis.

Obama said there was not yet a clear strategy in Syria. 

"The president was candid about the fact that the Pentagon is reviewing options military options that may be available to him," White House spokesman Josh Earnest said.

An Airstrike Campaign Widens

By September 2014, Obama made clear that the U.S. would continue and expand the battle against the Islamic State. The militant group had publicly executed American hostages on video and taken over large swaths of western Iraq and eastern Syria. Obama told the United Nations that those who joined the extremists should "leave the battlefield while they can," the New York Times reported, and he vowed that the U.S. would "degrade and ultimately destroy" the group.

He also said American advisers would help train Syrian rebels and U.S. airstrikes would help support their campaign. Despite expanding U.S. involvement, he has maintained: "We will not get dragged into another ground war in Iraq." Some said the president's statements were confusing, as he said the goal was to "contain" ISIS, while also saying the mission was to "destroy" the group.

The Campaign Sees Successes

During the third Oval Office address of his presidency, Obama reiterated his belief that ISIS will be destroyed. But unlike previous speeches, the president had gains to point to. As of December 2015, the extremists were losing their grip on some territories in Syria and Iraq. To date, the group has lost about 40 percent of their land in Iraq and 20 percent in Syria. 

However, ISIS was also extending its reach abroad, sparking calls for greater action, particularly from Republicans. The Oval Office address came following the San Bernardino, California, ISIS-inspired terror attacks, which left 14 people dead. While they were not believed to have had direct contact with ISIS, the killers did appear to be radicalized as well as supporters of extremist groups overseas. The episode also came a month after a deadly terrorist attack struck Paris, killing some 130 people. ISIS claimed responsibility for that attack in France.

Obama consequently affirmed that the U.S. strategy was working, vowing to continue airstrikes and support for allies on the ground.

"We should not be drawn once more into a long and costly ground war into Iraq and Syria. That's what groups like ISIL want," Obama said during the address. "The strategy that we are using now — airstrikes, special forces and working with local forces who are fighting to regain control of their own country — that is how we will achieve a more sustainable victory."

Obama Announces a Surge in American Forces to Syria

While visiting an industrial trade fair in Germany Monday, Obama announced sending an additional 250 troops to Syria. The forces will be there to help train and assist rebels fighting ISIS. And while they're not intended to be engaged directly in combat, they'll be fully geared up in case battles arise.

The move was expected to ramp up pressure on ISIS and continue ground gains against the group. It will also expand the presence of U.S. troops in Syria from 50 to 300. 

"They're not going to be leading the fight on the ground, but they will be essential in providing the training and assisting local forces," Obama said.