When a robot dies, you don't have to write a letter to its mother.

The best way to create cost overruns in any military acquisition is to change course midstream. That is exactly what Donald Trump wants to do here.

We are not getting rid of carriers any time soon. This is both because of their utility and also because of their role in Navy culture and in the defense-industrial complex. It is an academic debate.

What one Predator drone pilot described of his experience fighting in the Iraq war while never leaving Nevada: 'You're going to war for 12 hours, shooting weapons at targets, directing kills on enemy combatants. Then you get in the car and you drive home, and within 20 minutes you're sitting at the dinner table talking to your kids about their homework.'

The problem is not just the cost of the ships, but that the swapping was supposed to be quick, but right now it can take days or weeks, which is more like traditional refitting. But the model of modularity and being able to take on different roles is a good one. This is where adding in unmanned systems in the future will be an aid. If they can carry them onboard, whether it be drones to mine or sub-hunting underwater systems, all ships should be able to do such multiple roles simultaneously.

China is working on a similar system for its future carriers. Donald Trump may want to go back to 1920s-level technology, but the rest of the world isn't.

The drone war takes place 24/7, 365 days a year. The war doesn't stop on Christmas. It's like being a fireman when there's a fire every single day, day after day after day. That's emotionally and physically taxing.