John McCain confers with Charles Schumer. (AP Photo/J. Scott Applewhite, File.)

John McCain, who seems never to have met a country he didn’t want to bomb, now appears never to have seen a peace conference he didn’t want to wreck.

Speaking about the current plans to convene a conference on Syria involving both the government of President Assad and the rebels, and co-sponsored by the United States and Russia, McCain had this comment:

It’s fine with me to have meeting or gathering or conference or whatever it is. But the only way that the Russians are going to be cooperative on this effort is if they believe that Assad is losing. That’s why we should act before any conference takes place…. That means a no-fly zone, that means [giving] heavy weapons to the resistance.

Leave aside the snarky comment “or whatever it is.” (It’s a peace conference, and it’s a desperate, last-ditch effort to prevent catastrophic bloodshed and a regional crisis, Senator McCain.) By proposing to provide heavy weapons to the “resistance,” which includes Islamists of all stripes, some of whom are allied to Al Qaeda, McCain is essentially suggesting to sabotage the conference itself.

In a hopeful sign, Assad has provided Russia’s Foreign Minister Sergei Lavrov with a list of attendees for the conference. So far, at least, the rebels have not done the same, but Secretary of State Kerry is diligently working on the Syrian Free Army and the other Syrian groups to attend. Kerry warned Assad that if his side doesn’t take part in the conference, to be held sometime in the next few weeks, the United States will increase its aid to the rebel side and “unfortunately the violence will not end.” But that seems like a needless threat when, thus far, it’s the rebel side that hasn’t agreed to negotiate.

Let’s not underestimate the huge difficulties that stand in the way, with extremists and sectarian killers on both sides of the fight and a path to a settlement that is far from clear. It would probably start with a cease-fire, a suspension of arms deliveries to both sides, the provision of humanitarian aid across Syria, and a decision to negotiate indefinitely on what a transitional government might look like. That, at least, is what I see as the right way to go.

At least one rebel video shows a commander cutting open the body of a victim and eating what appears to be his heart. In the video, the monstrous fighter says: “You slaughter the Alawites and take their hearts out to eat them.” That’s not an act calculated to encourage comity on either side. But, of course, there are terrible atrocities on both sides.

The Alawites, who belong to an offshoot of Shiism, are fearful that the rebels—who are led by fanatical Sunni extremists and Al Qaeda types—will exterminate them if they are victorious. By the same token, widespread atrocities against Sunnis in Syria are being carried out by government forces.

Here’s more from what Kerry said yesterday:

I have talked with almost all of the foreign ministers in the core group who will be meeting next week together in order to lay plans for this negotiation. The members of the opposition have been in touch.… It’s only been five days since this was announced and a huge amount of work is already under way. When we announced it, we said towards the end of the month (of May) or early June. We expect it to be exactly that, somewhere in early June, I would hope, and that’s our current expectation.

We believe the … best way to settle Syria is through a negotiated settlement.

One key issue is whether or not Iran will be asked to attend. In 2001-2002, of course, Iran was powerfully helpful in stabilizing post-Taliban Afghanistan, though that cooperation dried up when President Bush decalred Iran to be part of his “axis of evil” weeks later. Because Iran is a leading backer of Assad, it would be very useful to involve Iran over Syria. Here’s a brief exchange from the State Department briefing yesterday with Jen Psaki, the spokeswoman:

QUESTION: Jen, can you rule out the Iranians participating? Were they invited?

MS. PSAKI: In terms of the participants, that’s being discussed now. I can’t tell you who is—who will be and who won’t be participating at this stage.

QUESTION: Do you have any problem if the Iranians attend the meeting?

MS. PSAKI: Again, I’m not going to parse that. We’re discussing this with the possible participants, with a number of people as we lead up to the planning for the conference.

So at least the Obama administration isn’t ruling out a role for Iran.

Read Robert Dreyfuss on the Moscow spy flap and why Ambassador Michael McFaul should be fired.