There are wars and then there are police actions and then there are invasions and then there are “surgical strikes” and then there is diplomacy.

It’s more than nomenclature, though, when considering American options in Syria.

Too many observers — mostly conservatives, curiously — have jumped on the peacenik train and sworn the United States to the sidelines. This is even as evidence becomes unmistakable — far more unmistakable than in the case of Iraq — that weapons of mass destruction are in use, now, by the Syrian government against its people.

Americans on both the left and right want to consider this Iraq II as a way to justify standing aside. But that’s just not the case.

First, there was far more diplomacy — even if for show — by the George W. Bush administration in Iraq than by Obama in Syria, as far as we know.

More importantly, although there had been plenty of evidence of chemical attacks against ethnic Kurds under Saddam Hussein, those attacks were ongoing over a period of years — decades — and were not what precipitated our invasion of that country.

What did precipitate our invasion of Iraq still isn’t altogether clear, trillions of dollars and thousands of wasted American lives later. Iraq never attacked us and was never linked to the Sept. 11 terror attacks. There was never any hard evidence the Iraqis were stockpiling chemical weapons. If there were, that evidence would have been long since been compiled and known to U.S. intelligence officials long before our attack.

In Syria, the evidence of a massacre is clear, present and undeniable … “bodies of the dead lined up on hospital floors, those of the living convulsing and writhing in pain and a declaration from a respected international aid group that thousands of Syrians were gassed with chemical weapons,” according to a news account in Thursday’s New York Times.

President Obama has infamously made using such weapons a “red line” for U.S. action.

Given the obvious humanitarian urgency, the recent escalation of hostilities, the endangering of the pro-democracy Arab Spring, the need to quell insurgent Islamists and the professed promise of U.S. military force against the Assad regime should it use state tools to attack its citizens, we are now faced with basically two options: invade, or strike at the facilities. Doing nothing is no longer an option.

It’s the latter option we would like to see. The United States needs to send a message in a nonlethal way that, when we say our policy is “no WMD in Syria,” we mean it. And we need to do it in a way that isn’t hypocritical — that is, it won’t cause more casualties than it would prevent, or spark an ongoing police action full of “mission creep.”

We favor the United States undertaking, in concert with our allies, small-scale air operations to destroy the facilities used to make and store chemical weapons inside Syria. The United Nations should then resolve to assess the aftermath, arrest suspects — including Assad — and try them at The Hague.

The president has been taking a far more cautious and circumspect approach to violence in the Middle East than his predecessors. By and large — for lots of reasons, from our own economic fragility to recouping lost respect — that’s been good policy. But evidence dictates a change in course, as there are risks of casualties either way.

Going hard after the weapons and facilities, prosecuting the offenders and ending the Syrian government’s assault on its own citizens will help create conditions for peace that do not exist now, help the Syrian democracy movement thrive, and defeat Assad’s brutal battle against Syrians whose democratic ideals must be given our full support.