The staff at Just Security weighed the questions of why National Guard troops were not stationed at the US Capitol prior to Trump’s “Stop the Steal” rally on January 6th and why they took so long to respond to the riot once it began in earnest and concluded that it’s quite possible senior military leaders did not want to hand Trump the firepower to seize control of Congress and prevent the certification of the 2020 election. They cite the evidence that it was concerns over “optics”, that they would want to prevent a deadly confrontation between troops and the MAGA horde, that certain officials wanted to let the Capitol riot happen, bureaucratic inertia, or some combination of the above as insufficient explanations for why the day happened the way it did.
They believe that the Department of Defense held back because they had reason to believe Trump would have used the presence of troops there to declare an emergency and then somehow use the troops to maintain power, likely via the Insurrection Act, writing “With respect to planning for Jan. 6, the publicly available evidence to date very strongly suggests that the senior defense officials’ concerns led them to impose unprecedented constraints on the authorizations and substantive conditions for use of the Guard – Miller admitted as much. Those constraints help explain the substantial delay in sending a first group of Guardsmen to the Capitol. What’s more, the evidence also indicates that the same concerns potentially explain why the Pentagon did not approve deployment of the National Guard in sufficient time – and, indeed, authorized the deployment only after President Trump eventually made a public announcement (at 4:17 pm) that he was not in favor of continued occupation of the Capitol” before going into a lengthy timeline.
It’s a hell of an account and it is very well documented. Check it out if/when you have the time.