Mix hydrogen and CO2 to produce light hydrocarbons, which can then be processed into jetfuel. Seawater contains CO2 and hydrogen; if you have enough energy, you can break water molecules apart. Imagine an aircraft carrier scooping up CO2 from seawater, cracking the hydrogen from it, and replenishing its jetfuel tanks. Now the flattop would need to leave station to replenish only when it needed more bombs and missiles.
Link:
http://blog.usni.org/?p=4071
Link:
http://blog.usni.org/?p=4071