Contrary to the Orwellian reasoning of Secretary of State John Kerry, launching missile strikes on a foreign country does constitute war. Opponents of a U.S. attack on Syria argue that Syria does not pose a credible security threat to the United States, and the bulk of the evidence supports their conclusion. And for foreign policy realists, the absence of such a threat is sufficient to reject military action.

But many war advocates contend that even if the Assad government does not directly threaten America’s security, the regime’s alleged use of chemical weapons on innocent civilians is an outrage that warrants a U.S.-led punitive response. Those who take that position should at least ask hard questions about the source and reliability of the intelligence information.

Specifically, they should insist on knowing how much of the information was gathered directly by U.S. intelligence agencies and how much was obligingly provided by third parties who have their own policy agendas and ulterior motives. That is an extremely important consideration. Countries such as Turkey and Saudi Arabia are the principal sponsors of the insurgents seeking to oust Bashar al-Assad’s government. Although Israel is more ambivalent about the Syrian rebels, Israeli loathing of the Assad family goes back more than four decades and Israeli leaders want to see Washington take an even more active military role in the Middle East. Information that such sources provide is hardly unbiased and should be assessed with caution.

That is doubly true of any intelligence that the Syrian rebels provide. Not only does that faction have an obvious, massive incentive to have Washington intervene militarily against Assad’s forces, but the insurgents have already been caught peddling bogus atrocity stories. The most notorious example was the attempt to use nearly decade-old photos of slaughtered civilians in the Iraq war as “evidence” of Syrian army abuses. Given that track record, alleged intelligence from rebel sources should have virtually no credibility.

Obama administration officials are insistent that information about the Assad regime being responsible for chemical attacks is indisputable, and that this case is nothing like the fiasco of the faulty intelligence that led to the Iraq war. But of course, we were told that the Iraq intelligence was rock-solid at the time, so that assurance is less than compelling. Moreover, it is important to remember that most of the phony evidence of Saddam Hussein’s supposed weapons of mass destruction was supplied by Iraqi exiles, specifically the notorious (and aptly named) source “Curveball” that the Iraqi National Congress produced. We must be doubly careful not to be manipulated in that fashion again.

The time to ask rigorous questions is before the missiles start flying. It is small comfort to know after the fact that we entered the Iraq war based on erroneous information. Given that precedent, it would be shameful to be fooled in the same way with regard to Syria.