Valid (if scary as hell) point.
I think we’d win if they were stupid enough to take us on, and if we took the thread seriously. If not, we could very well lose.
Since the OP is basically talking about ship-to-ship GUN battles (which have missiles and support aircraft have basically eliminated) … what about the likelihood that non-missile aerial dogfights will ever again take place? Are fighters ever again going to blast away at each other with guns? Or are fighters ever going to shoot down bombers with guns again?
Fine, be the voice of reason… be that way! 
Ship to ship gun battles in future are incredibly unlikely (IMO of course), but could be possible if we reach the point in future where we have so many measures and countermeasures that missiles are no longer effective (a long way off IMO) in which case a dumb projectile fired from a cannon would do just fine. For instance, firing a radar-guided missile into a cloud of chaff is pretty much useless, but if you know where the ship is you could fire a cannon shell into that same cloud and it would have no adverse impact on your targeting. You just have to know exactly where he is, exactly how your rounds perform and exactly how fast both he and you are travelling; the rest is just math. Of course the problem is finding him, hence why missiles are still the most effective ship-to-ship weapon.
Fighter aircraft still do blast away at each other with guns, for exactly the reason stated above - too much electronic countermeasures renders guided missiles inefffective but a spray of dumb 20mm rounds doesn’t care. I can’t find the stats, but a decent percentage of the (admittedly small) number of air to air kills in Gulf War 1 were from guns, not missiles, and all Air Force and Navy pilots train extensively in dogfighting with guns at places like Red Flag in Nellis AFB and Top Gun at Miramar. When the F-4 Phantom (originally designed as an interceptor against Russian fighters and bombers) was first developed, it did not have a gun. Air combat over Vietnam proved how stupid this was and gun pods were quickly developed and deployed for the F-4. Later revisions of the F-4 and all future models of F-16, F-18, F-15, etc… all have internal 20mm gatling guns. The Air Force wouldn’t waste money and space on fighter gun systems if they didn’t have some use for them.
Bombers can be simply loaded with electronic counter measures, hence why it might be easier for a fighter to shoot one down with Mark-1 Eyeball and Gun than using his super-advanced missile system. Of course, nobody’s left who could use bombers against us in this way, so I doubt this is gonna happen anytime soon.
Just a nitpick - Miramar has now been fully converted to a Marine Corps Air Station after the closure of El Toro and Tustin. And if Tom Cruise were to do that movie today, it would be filmed in dusty, boring Fallon, Nevada.
Right down the road from where the Air Force has it’s version of Top Gun (called Red Flag) at Nellis AFB. Both are kind of near Nevada, but other than that not a lot of fun to be had at either one unless you’re a pilot…
Duuuh… Near Las Vegas. They are IN Nevada. :smack:
Technically you’re right, a railgun is not truly a DEW, those are lasers, masers, particle beams ect. However the Navy seems to be lumping railguns together with proper DEWs for research purposes because they have much in common from a platform requirement standpoint. The weapon would be used primarily for offshore bombardment, but could also be used for anti-ballistic missile, anti-aircraft and anti-ship purposes as well depending on design. A Laser weapon has drawbacks from a naval standpoint, for one thing it’s direct line of sight only… no over the horizon capability for ground targets and common atmospheric conditions at sea would inhibit the use of most kinds of lasers. The solid tungsten railgun projectile delivered at 3km a second would obliterate all but the most hardened of targets. The rates of fire and magazine capacities possible with a railgun would make them far safer, cheaper and more deadly than a modern chemical projectile weapon or missile.