I do think we are seeing the definition of what is a carrier changing. You can turn America-class amphibious assault ships into smaller, less expensive versions of carriers. You can equip surface ships like destroyers as well as submarines with not just missiles and torpedoes but drones than can do roles traditionally performed by carrier aircraft, like surveillance or even strike, such as finding and taking out opponents' missile batteries.

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.

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

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.'

It is utterly inappropriate for the president Donald Trump to be weighing in the design and acquisitions process of carrier ships at this level. Had a Democratic president done this kind of micromanagement, all the more so in public, Republican defense wonks would have been apoplectic. Instead ... crickets.

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.

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.