So what's your proposed solution? Not have a military and just roll over when someone decides to attack you?

My proposed solution is understanding what this scene means:

In front of a blood-stained chessboard littered with mutilated chess pieces finely dine two royal couples - black and white - cheering their endgame.

If the civilian populous has access to arms and armories they can make it a worthless proposition to invade them. Its not like the world is entirely composed of large countries with strong militaries already. An insurgency can last decades under fire from a superior force, an organized military won't. So if you can't match the organized military might of potential enemies, its probably mostly a waste to try.