 Less than four years after the withdrawal of American troops, Iraq is once again descending into violence and chaos. A breakaway faction of Al-Qaeda known as ISIS has seized large swaths of northern Iraq and is marching toward Baghdad. The Sunni insurgents say they want to establish an Islamic state that would span parts of Syria and northern Iraq. The Iraqi government has reportedly requested air support from the United States, but President Barack Obama has so far proceeded with caution. Ending the Iraq war has been a cornerstone of Obama's administration. When he was running for office, Obama campaigned on the need to wind down the war. In 2011, Obama announced the end of U.S. combat operations in Iraq, the last American troops left the country by December. It's difficult to quantify the cost of war, numbers vary depending on how you count, but a conservative measure says that more than 189,000 people have died in the fighting that followed the March 2003 invasion, with the vast majority being civilians. As for the financial toll, that's been estimated at $1.7 trillion, with several hundred billion more due to be paid in veterans care. After eight years of war in Iraq and a longer one still winding down in Afghanistan, Obama has been taking a more cautious approach to intervention overseas. Just because we have the best hammer does not mean that every problem is a nail. Because the costs associated with military action are so high, you should expect every civilian leader and especially your commander in chief to be clear about how that awesome power should be used. But then in June, things in Iraq took a dramatic turn. On June 10th, after days of fighting, the Islamic State of Iraq and Syria, or as it's better known ISIS, seized Mosul, Iraq's second largest city. ISIS then took control of Tikrit, hometown of Saddam Hussein, and the Tal Afar. When they took Mosul, the militants freed prisoners, burned army vehicles, and robbed banks of hundreds of millions of dollars. In YouTube videos, ISIS promised to take over Baghdad. This is President Obama days after ISIS took the first two cities. We will not be sending U.S. troops back into combat in Iraq, but I have asked my national security team to prepare a range of other options that could help support Iraq security forces and I'll be reviewing those options in the days ahead. I do want to be clear though, this is not solely or even primarily a military challenge. At the time, there were still about 200 American troops stationed in Iraq to guard the U.S. Embassy in Baghdad, according to the Wall Street Journal. And this week, Obama sent 275 soldiers to reinforce them. The U.S. has also sent an aircraft carrier and other warships into the Persian Gulf. Surveillance drones and manned navy aircraft have been reported flying over Iraq to gather intelligence, and Obama is reportedly considering drone strikes against ISIS. However, given Obama's previous limited responses to conflicts in Libya and Syria, it's unlikely that the president would turn to any of these options lightly, if at all. American forces will not be returning to combat in Iraq, but we will help Iraqis as they take the fight to terrorists who threaten the Iraqi people, the region, and American interests as well. Obama has a handful of non-military options, which could even include cooperation with longtime adversary Iran. The U.S. is continuing to push Iraqi Prime Minister Maliki to implement more inclusive policies in Iraq. Failure to do so, experts say, made it easier for ISIS to garner support among the disillusioned Sunnis. But even that may not be enough to save Iraq from chaos. Since his days as a senator, Obama has spoken about the need for less military intervention abroad. But as Iraq teeters on the brink of sectarian war, he's finding himself reluctantly returning to the country. The question he faces now is how to stabilize the country without getting pulled back into a conflict that's already proved so costly in lives and money.