Assuming Mexico does nothing further to stop them, how long will it take the Honduran caravan to reach the American border? That’s how long the military has to figure out what they can do about it in keeping with the President’s recent orders. Yesterday, Defense Secretary Jim “Mad Dog” Mattis told reporters that he’s on top of the situation and is already staging troops and equipment to head south. The details of the plan, however, appear to still be rather vague. (Washington Post)

The U.S. military has already begun delivering jersey barriers to the southern border in conjunction with plans to deploy active duty troops there, U.S. Defense Secretary Jim Mattis said Sunday as a caravan of Central Americans slowly heads across Mexico toward the United States.

Mattis told reporters traveling with him that details of the deployment are still being worked out but he should have them Sunday night. They will include exactly how many forces are needed.

The additional troops will provide logistical and other support to the Border Patrol, and will bolster the efforts of the approximately 2,000 National Guard forces already there. The new forces are expected to provide logistical assistance such as air support and equipment, including vehicles and tents.

First, let’s tackle the question of timing. If we assume that the caravan can make, at best, 20 miles per day on a forced march and they have roughly 1,000 miles to go to reach the Texas border, that’s nearly two months. That should be plenty of time to get set up, but we’ll also likely have a lot of troops sitting around without much to do for weeks on end. Of course, if they’re relying on jersey barriers for temporary walls, there’s lots of work to be done. Also, those barriers really aren’t very high and won’t stop determined people from going over them.

But what if the migrants opt to swing to the west and try to cross at Tijuana? They’ll get a much warmer reception from the California state government than they would in Texas, but it will nearly double the amount of time until they arrive. So at that point will Mattis have to dig up all the Texas barricades and ship everyone to California? This could turn into a very expensive, chaotic operation rather quickly.

I’m also still not entirely clear what the troops will be doing. Yes, they can do construction work on the temporary barriers and they can take over certain office jobs for Border Patrol agents, freeing them up to go into the field and deal with the migrants. But they can’t actually arrest anyone. And they clearly can’t cross over the border into Mexico if any migrants have to be pursued. We’d have an international diplomatic crisis on our hands at that point.

I still support the President’s intention to do everything possible to secure the border and fend off the incoming wave of caravan participants so everyone can be processed in an orderly fashion. But we need more details as to precisely how the military plays into this strategy in a safe and legal fashion. As I said above, we have some time to work out the details, but that situation won’t hold forever. And we clearly need something a lot better than jersey barriers along the border.