I've done two government contracts, just one for defense.

I won't ever take a defense contract again because the primary contractor selected the wrong part, then hired me as a subcontractor based on my expertise with a part they should not have selected.

This actually came to the point that I spent six weeks furiously trying to find a workaround while they burned a bunch of money making prototype assemblies that did not work, then delivering them to "The Client" with the expectation that they would integrate my firmware later.