Though it's pushing hard for authorization to launch missiles into Syria, the White House seems to be in no particular hurry, saying that strikes could happen pretty much at any time. That's different from previous conflicts, which could take months to plan and put in motion. We asked Anthony Cordesman, who holds the Arleigh A. Burke Chair in Strategy at the Center for Strategic and International Studies, to explain what this might actually look like. 

Lydia DePillis: What does it even mean to be in a state of readiness indefinitely? 

Anthony Cordesman: First, just as a basic structure, when the U.S. deals with any potentially hostile state, it develops contingency plans that it constantly updates. It also updates what's called the target list. When we are involved in a situation where we are at least on some level helping the more moderate rebel groups — and we are — we are going to generate that data regularly. The Syrian order of battle is also critical to Israel, to Jordan, to Turkey. It's not a matter of suddenly generating a plan. You may have to update one. But the other issue is, the U.S. can bring together a wide range of intelligence assets, and do so with much more detail, without taking any visible action. All you have to do is extrapolate from a lot of what's been reported in The Post to get an idea of what our continuing coverage is.

The other thing is, when you talk about a cruise missile system, a GPS-determined system can be reprogrammed in near real time. That means to set up a target structure based on the fixed facilities of a high-value regime is something you can do almost instantly. And as your intelligence evolves, you can constantly change that. The same is true today of virtually all aircraft. You can actually reprogram the target structure in an aircraft in flight. You can alter the vector of a stealth aircraft in flight and do it covertly. In other words, they wouldn't pick up the signal. So this is a very different world from even the first Gulf War of 1990-1991, where it could take days to redo the target list. And particularly because we're not dealing with mobile ground forces or mobile air units. The very nature of a cruise missile means you're using it against a fixed target.

LD: So where would those missiles come from?

AC: The president has focused on five cruise missile destroyers. At least four are in the eastern Mediterranean, and the fifth is closing. So basically, they're on site, ready to launch. Now, to be careful: We will not announce other strike systems if we plan to use them. You're not going to tell Syria you might use stealth. You're not going to give them any warning as to what ordnance you might use.

LD: That information's totally classified?

AC: Operational information is extremely sensitive and highly classified. And every time I've seen a press article indicating that they were releasing one, they didn't know what they were talking about.

LD: What forms could those different strike systems take, though, hypothetically?

AC: You could make the obvious statement that they might involve stealth aircraft. But beyond that, I do not think it's in the public interest to really describe options.

LD: So how does being able to stay in a state of readiness for a long period of time impact the calculus of whether or when to take action?

AC: Any major movement of ships, aircraft, people is a matter of time and capacity. It's a matter of how ready the units are when you give the order. It's a matter of where you can land them, how you can base them. To prepare for the liberation of Kuwait took about half a year. To prepare for the deployment that went into the 2003 war, in physical terms, took about three months. So every single military action has a different time window. You could put special forces into an area in, say, 48 hours. The more time you have, the better equipped they would be. If they're forward deployed, they can react very quickly. Moving a division takes at least 10 days, and probably two weeks. So there are no magic numbers.

LD: Is it also harder to stop a military action in those kinds of situations?

AC: No, we've done it again and again. This is not World War I. We will never get ourselves into a box where somehow our interests change but we will somehow go ahead because the plan forces it. That kind of structure doesn't exist. You can always, today, halt or pull the force back before you use it. The only time you really created these situations was in World War I because of the rail schedules. There was a fixed plan; once you started it, nobody knew how to stop it, because the risks of the other side gaining an  advantage were too great. Now, you can run through an infinite list of contingencies where you might be moving up to the edge of war and go ahead by mistake. But that's very different from, "Hey there isn't any reason to do this, stop."

LD: And just to refresh our memories, how was that dynamic at play in the 2003 invasion of Iraq? I seem to recall that the troop and equipments movements required took on their own momentum

AC: You were conducting a massive movement of troops, aircraft and ships. So you had to plan the logistics, plan the supply, you had to load the aircraft, you had to load the ships, you had to train the combat units, you were talking about basically what it was, a significant regional conflict. This is using assets you have on the scene. To fire something from where you're sitting is very different from moving hundreds of aircraft, tens of thousands of men, thousands of pounds of armor, masses of equipment, all the way from the United States.

LD: But it could have been stopped at the last minute?

AC: Sure.