The US in it's current configuration requires an enemy. An enemy is like food, without one it will starve. So much of what makes the country run requires war. It's a common talking point, the MIC, deeply entrenched into the political system.

Politically the US is incapable of pivoting it's defense industry towards non defense use. It theoretically could with a fearless political movement, shift defense research into energy, materials, etc but it won't because a large aspect of the industry is the veteran to contractor pipeline and the military attitude carries over. Everything is a mission, a fight, good guys, bad guys, allies, and enemies. It's the backbone of the industry, the GI bill for make-work.

In order to pivot that deep culture of make-work to civilian use cases, the book would need to be rewritten. The US would suddenly need to be okay with social uses for research, development, and manufacturing. This would mean the gov would be in direct competition with greater industry, which would be a massive contradiction for the political classes and their intermingling with business.

Currently, the only customer for the massive defense industry is the the military. They're the only ones allowed to buy the product, and their wallets are deep.

Tl;Dr they can't stop this train. The only way forward for them is war, and war requires an enemy. The train could be stopped, but it no longer has brakes of its own. The ensuing derailment would be catastrophic and politically untenable. To any politician, if they want to make any changes period, they need allies. Without allies they can't make any changes.

Even the best politicians must operate within their political system and need to make tradeoffs in order to prioritize their goals. Kamala must suck up to the military if she has any hope in implementing the most minor incremental changes.