In 2011, President Obama was pilloried for, in the case of NATO's action in Libya, refusing to formally invoke the War Powers Resolution, which requires 48-hour notification to Congress anytime the United States participates in a war that Congress has yet to authorize. After such a formal invoking, the president would have 60 days to do the job before Congress had to give its assent.
The administration said that its actions in Libya were mostly "non-kinetic," was in service of a U.N. resolution, didn't involve troops on the ground, and ultimately the NATO coalition that helped the country finish off its revolution was not led by an American commander. Most of the materiel involved in the Libya conflict belonged to the category of ISR — "intelligence surveillance and reconnaissance" and EW — "electronic warfare," although the latter was absent from public administration descriptions of U.S. participation.
Presidents don't like the War Powers Resolution and Congress likes to give Presidents headaches for their refusal to follow the spirit of the pact, which the executive branch deems as unduly constricting on their Article II responsibilities to protect and defend the nation. Still, the White House insisted it was not simply shrugging off the responsibility to follow the law. It seems that the way the Libyan conflict played out did not fit within Congress' traditional understanding of what "war" actually was. Problem here: The definition of what constitutes military action is always changing. We are entering an era where precision strikes using non-manned drone airplanes is often the tip of the spear. Congress in 1973 certainly didn't envision that. But it clearly wanted to preserve an ability to at least provide a check on the president's power to utilize American troops for significant periods of time in pursuit of controversial policy ends.
Recently, the administration has begun to shift the grounds of the debate a bit. A few days ago, a single United States military aircraft was tasked to help the French in their campaign against a surge of al Qaeda activity in Mali. The aircraft did not engage anything. But Obama nonetheless told Congress that the U.S. had "provided limited technical support to French forces." These forces were attempting to rescue a French commando in Somalia. He has also responded to Congressional requests for information about U.S. special operations forces campaigns in Africa with thumbnail descriptions of what he has instructed the military to do. Last June, it acknowledged participating in direct combat operations against an al Qaeda linked group in Somalia.
There is an inconsistency here that the administration won't explain. Their steps toward some transparency are laudable; I suspect that the president is trying to strike a balance between notification and submission; the earlier he tells Congress officially, the less concern they will have in the future. As a precedent, this makes sense from the point of view of the executive branch, but it does not address military support to CIA covert actions or really provide any sort of guide as to what types of conflicts will trigger notification. (Perhaps it has something to do with the chance that U.S. citizens would be harmed by the participatory activity.)