Obama says that airstrikes in Iraq could continue for months:

President Obama sought to prepare Americans for an extended presence in the skies over Iraq, telling reporters on Saturday that the airstrikes he ordered this week could go on for months as Iraqis try to build a new government.

“I don’t think we’re going to solve this problem in weeks,” Mr. Obama said before leaving for a two-week vacation on Martha’s Vineyard. “This is going to be a long-term project.”

I suppose this is more honest than pretending that U.S. involvement will last only “days, not weeks,” as Obama claimed at the start of the Libyan war, but this just confirms that even the most “limited” interventions aren’t all that brief or limited. As we know from previous interventions, the initial estimates of how long they will last and what they will cost are frequently wrong. If the administration expects that this “project” will last several months, it will most likely continue for a lot longer than that, and it will end up being a larger commitment that originally advertised. There is already reason to expect that it will become a larger commitment in the future:

“There has to be a rebuilding and an understanding of who it is the Iraqi security forces are reporting to, what they are fighting for,” he added.

Once that happens, Mr. Obama suggested, the American military, working with the Iraqi and Kurdish fighters, can “engage in some offense.”

This is how even the smallest interventions can grow over time as new goals are added and the original limits are cast aside in favor of an expanded mission.