.- As the United States sends more troops to Iraq to help retake Mosul from the Islamic State, Catholics can view the action as just even while remaining vigilant about the long-term mission, one moral theologian said.

“Political order is a good that the just war theory affirms, and our efforts to assist the Iraqi government in bringing increased stability to Iraq is part of our ongoing responsibility that traces all the way back to our original intervention in Iraq,” Dr. Joseph Capizzi, a professor of moral theology and ethics at the Catholic University of America in Washington, D.C., told CNA.

The move should be seen as the U.S. trying “to remove ISIS from Iraq,” he said, noting that the terror group is “a threat to the stability of that entire region,” as well as that of Europe and the U.S., “and stability is a good,” he added.

On Monday, Defense Secretary Ash Carter announced the U.S. would be sending 560 troops to Iraq to help the Iraqi Security Forces. Part of the mission would provide “infrastructure and logistical capabilities” at an airfield recently captured by Iraqi troops 40 miles south of Mosul, to help the Iraqis retake the country’s second-largest city from the Islamic State.

“So the idea is that these new U.S. forces would be used to secure the airfield and essentially get it up and running as a logistics hub that would support ongoing operations by Iraqi security forces,” White House press secretary Josh Earnest said at the July 11 press briefing.

Some troops would also act as a “security envelope” for the Iraqi forces, Carter said.

Mosul, in the northern part of the country, has been in the hands of the Islamic State since the summer of 2014 when its forces displaced hundreds of thousands of residents, many of whom left with little to no possessions.

The 560 newly deployed U.S. troops will join the more than 4,000 already in Iraq.

Catholics should be wary about increases to the number of soldiers there and of any “mission creep” that results from the U.S. presence, Capizzi warned.

“There’s just a lack of forthcoming about how many troops are there, and what the nature of the commitment is,” he noted. “And that’s not a good thing. It sort of shadows how involved the U.S. military is or needs to be.”

“It’s something Americans should be vigilant about,” he added, saying citizens should be “tracking the nature of America’s involvement here” since “it’s not going away.”