We know how to kill aircraft carriers—or at least we know how best to try to kill aircraft carriers. Submarine-launched torpedoes, cruise missiles fired from a variety of platforms and ballistic missiles can all give an aircraft carrier a very bad day. Of course, modern carriers have ways of defending themselves from all of these avenues of attack, and we don’t yet have any good evidence of the real balance between offensive and defensive systems.

But what of the future? How will we plan to kill carriers thirty years from now? Here are five problems that the next generation of aircraft-carrier architects will need to worry about.

Submarines have long posed the deadliest threat to aircraft carriers. In World War II, every major carrier fleet suffered losses to submarines; in the Cold War, the U.S. Navy viewed Soviet subs as a critical problem. Against modern antisubmarine warfare capabilities, the biggest difficulties faced by a submarine involve finding a carrier, then getting into firing position (with either missiles or torpedoes) before the carrier’s aircraft and escorts can detect and kill the sub.