First it was 800 troops providing logistical support, then five thousand to secure it. Why stop there, though? Earlier today, Donald Trump pledged to send as many as fifteen thousand troops to the southern border in response to several migrant caravans from South America.

In other words, don’t knock on our border and expect to succeed at trick-or-treat:

“We have about 5,000. We’ll do up anywhere between 10 and 15,000 military personnel on top of border patrol, ICE [U.S. Immigration and Customs Enforcement], and everybody else at the border,” Trump told reporters on the White House South Lawn on Wednesday. …

“I’m not fear-mongering at all. Immigration is very important,” Trump said.

Just how seriously should we take the rapidly escalating numbers? It has the sound of extemporaneity to it, as though Trump is upping the ante rhetorically just to prove how serious he is about stopping the caravans. However, the commanding officer of Operation Faithful Patriot told reporters yesterday that he’d already been planning for more than the 5200 Trump authorized:

The top U.S. general in charge of the deployment — dubbed Operation Faithful Patriot — told reporters earlier this week that he expects additional active duty troops will supplement the 5,239 already slated to deploy, depending on future CBP requests.

“There will be additional force over and above 5,239,” Gen. Terrence O’Shaughnessy, the head of U.S. Northern Command, said on Tuesday. “The magnitude of that difference I don’t have an answer for now because we don’t know what that answer is.”

However many get deployed, don’t ask James Mattis about it being a stunt. He informed reporters today that he doesn’t do “stunts,” and that people had better take this deployment seriously:

Defense Secretary Jim Mattis emphatically denied a reporter’s suggestion Wednesday that the deployment of approximately 5,200 active-duty troops to the U.S.-Mexico border is part of a political stunt ahead of next week’s midterm elections.

“We don’t do stunts in this department. Thank you,” Mattis told a reporter who posed the question after a Pentagon meeting with Mattis’ South Korean counterpart. The defense secretary added the deployment was to provide “practical support” to the Department of Homeland Security and was based on a request from U.S. Customs and Border Protection.

As Fox News notes, though, the massive numbers of troops might run out of tasks to accomplish. The US military is restricted in their abilities by the Posse Comitatus Act, forbidding them from performing any police or detention role on US soil. What can they do? Doing what the National Guard’s 2000 troops are doing now — “providing helicopter support for border missions, installing concrete barriers and repairing and maintaining vehicles.”

One can see why 800 troops would be insufficient for that task on a 2,000-mile border, and why 5,200 would be a better fit. But sending 15,000 active-duty troops to build tent cities, install concrete barriers, and fix trucks? That seems like overkill for the tasks available for them, at least on our side of the river. If I were in Mexico’s military command, I might be wondering why a full division of the US Army was sitting on the other side of the border.