I agree that it does seem like humanity needs to evolve morally, but there is another option. Instead of forcing people to participate, create a voluntary system that people seek out on their own. Offer a quality service like any good business does and people won't have to be tracked down to pay taxes, they will bring you their money to keep your services going.

The mental hurdle to get over is that if someone doesn't want your services (e.g. military protection or healthcare), then you have to allow them to leave your system. If you offer a quality product that they really want, then you'll attract paying customers.

Now you're probably thinking that nobody is going to pay to have an aircraft carrier and a hundred tanks sitting idle waiting for the Russians to invade north america. Maybe thats because it's not what the future of humanity will be. I don't think the Russians or Chinese really ever plan on taking over Iowa and Kansas, so it's probably time to decommission all those expensive weapons. Thats how a free market determines what services are really needed in the world.