What happens to federal military equipment and weapons stationed in Texas?

It gets settled at the negotiating table, the same as every other asset question. Some equipment stays with Texas, some is purchased or transferred, some leaves with departing United States forces. The split is a matter of orderly accounting, and it does not determine whether Texas can defend itself.

Who owns what today

The equipment at U.S. installations in Texas belongs to the United States, and so does most of what the Texas Military Department handles day to day. Under 32 U.S.C. 710, military property the United States issues to a state's National Guard remains the property of the United States. Texas holds custody and operational control. Washington holds the title. What the Texas State Guard buys with state money is Texas property outright and stays that way, but the heavy equipment of the Texas Army Guard and the Texas Air Guard sits on federal title. That is why this is a negotiation rather than an assumption in either direction.

How countries actually divide military equipment

Every peaceful division of a country in the modern era has run on the same two rules: immovable property goes to the country where it sits, and movable property is divided by agreement, usually in proportion to population. Those rules are written down in the 1983 Vienna Convention on Succession of States in Respect of State Property, Archives and Debts, which never entered into force for want of ratifications. Governments follow them anyway, because they are what parties converge on once they are actually sitting at the table.

Czechoslovakia, 1993

Czechoslovakia is the closest analog to a negotiated Texas exit, and it went exactly that way. The country divided on January 1, 1993. Buildings and installations went to whichever republic they stood in, and movable federal property, army equipment included, was split two to one, Czech to Slovak, matching the population ratio. Much of the hardware and many of the units had already been repositioned before the split date, and compensation was paid where the division left one side short. The Czech Republic was in NATO by 1999 and Slovakia by 2004.

The Soviet breakup

The Soviet dissolution followed the territorial rule more bluntly still. Ukraine inherited roughly 780,000 troops, 6,500 tanks, about 7,000 armored combat vehicles, 1,500 combat aircraft, and more than 350 ships, for the simple reason that those forces were stationed on Ukrainian soil when the union came apart. Where ownership was genuinely contested, principally the Black Sea Fleet, it was settled by treaty in 1997.

What Texas carries into the negotiation

The installations are immovable and they sit here. The movable equipment is negotiable, and Texas comes to that table holding more than 31 million people, a $2.77 trillion economy, and a list of things the United States wants badly: continued access to the installations, overflight and training rights, Gulf port access, and an intelligence relationship. The mutual defense pact described in the bases answer is the likely container for all of it, including a transition period where equipment stays where it is under joint command until Texas forces reach full readiness.

Texas builds this equipment

There is also the matter of where the hardware gets made, which the assumption that all of it leaves skips entirely. Air Force Plant 4 in Fort Worth runs the F-35 final assembly line, all three variants, the largest fighter production operation in the world. Bell assembles the V-22 Osprey in Amarillo, every variant, and will build the Army's MV-75 there. Corpus Christi Army Depot is the largest helicopter repair facility in the world, with more than 5,900 employees overhauling the UH-60, CH-47, and AH-64 fleets. Red River Army Depot in Texarkana rebuilds ground combat vehicles. Texas would not be importing its way to a military from a standing start, and the United States would still be a customer.

What cannot be known yet

The exact inventory, unit by unit, that ends up in Texas hands on Day 1 cannot be specified today. That comes out of a negotiation that has not happened, and any number offered now would be invented. The rule that negotiation runs on, the precedents that set it, and how much of the equipment Texas already builds are all knowable now.