Actually to sum it up, the use of warship is to project power through sea. The combat range of warship is far beyond the reach of regular fighter jets, and their payload is also far beyond even a medium sized fighter jet squadron. Basically you can use warships to strike through sea to where your other weapon platforms can't reach. It is also a platform with attack and defense in one. It is never easy to sink a warship, unless you are putting it in a controlled environment such as one lone warship against an entire air force.