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The fall of the Iraqi capital of Baghdad to ISIS forces is one of the (many) enduring fears that has persisted throughout the radical Sunni group's summer campaign.

Late on Monday, it was reported that the new American offensive included an airstrike against ISIS installations near the edge of Baghdad, which was something of a surprising development. As NBC News said of the strike that hit just southwest of the city:

The airstrike Monday near Baghdad was more offensive in nature and was not triggered by any advance of ISIS toward the Iraqi capital, a defense official said.

But following a "war summit" in France held earlier in the day between U.S. Secretary of State John Kerry and a mishmash of diplomats from European and Middle Eastern countries, the escalation was also symbolically noteworthy. As Steve Kenny reported:

The strikes, the Pentagon said, go beyond the United States’ initial mission announced last month of “protecting our own people and humanitarian missions.”

The strikes on Sunday and Monday involved both attack and fighter aircraft, which the Pentagon said destroyed six vehicles near Sinjar and an ISIS combat post that was firing on Iraqi troops.

Meanwhile, the perils of the American-led offensive came into clearer view as senior administration officials signaled that American troops wouldn't hesitate to act against Syrian regime forces if they fired on American planes. The AP relayed comments by White House spokesman Josh Earnest that more or less said the same:

Asked Monday about the prospect of striking Assad's regime if his forces were to target Americans, White House spokesman Josh Earnest said there will be "rules of engagement that are related to any military orders the president directs."

"It won't surprise you to know that there are contingencies related to self-defense when it comes to these sorts of rules of engagement," he said.

While Syrian dictator Bashar Assad has threatened to confront American planes if they violate Syrian airspace, the likelihood that the Syrians would actually follow through, given their limited capabilities, seems small. Instead, Obama officials may have been sending a message to America's Sunni allies that the Assad regime, which is backed by Shiite Iran, isn't whom the airstrikes are designed to benefit.

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