Re: Worth it?
"I can't imagine for one minute any other nation ally or not, who would be willi g to put their expensive toys at risk to protect ours. Not in a real war."
I guess it's because you don't understand the way these things work perhaps you should read up on some military history?
A bunch of countries with different capabilities "ally" themselves. These "Allies" provide different bits of any given task force...
Country A has a bunch of Frigates (say) but no Air cover, country B has a load of air cover but not many frigates... so country A says to country B "Hey, give us some Air cover and we'll protect you with our Frigates!" That's how being "Allied" works... for other real world examples see pretty much any armed conflict from history.
For what it's worth, I seriously doubt that we would ever find ourselves in a shooting war with either Russia or China. Russia's only aircraft carrier is followed around by a bunch of tugs and a ship full of spares.