I have an awesome pet rock I will rent to you for $1,000 a day. You never know when it might come in handy!
Listen, it's the nature of defense. Almost every nation in the world has an army. Most nations don't use them for much. So it makes sense having a small army as it never gets used. But then again, the purpose of an army is to defend the realm. And once you actually need it, it won't work properly if it's too weak.
So on one hand, you want it to be cheap because you don't use it. On the other hand, you want it to be strong for when you need it. No matter how strong a peacetime army is, you'll always want it stronger if war breaks out.
My parents have insured their house in case it burns down. It hasn't so far, and chances are, it won't. Why bother with insurance, then?
As for the pet, I'd prefer a cat. Mooaaau.
To have a "balance of power" a emerging power or two would be needed. Right now we have one single superpower, the USA. That's not a balance of power but a classic empire.
Better be prepared for it. The US doesn't have an empire right now, but the US is involved in places. That's different.
Right now, China is becoming a strong counterweight to the US. Economically for now, but in years to come, China might have a blue ocean navy and "interests" in Africa to manifest. That's when we WANT a US carrier group in the Indian Ocean.
Regarding 1919 and the horrors of Nazism that followed: If the Legue of Nations, not unlike todays UN, would not have been intentionally weak because people who believed in
Realism constructed it that way, it would have helped more than the NATO.
NATO were able to act in Kosovo, the UN would never have. Hitler was mad, but he wasn't that mad.
Costly? To whom? The European members are spending a pittance on defense with the U.K. leading the pack at a staggering (lol) 2.7% of GDP. That is nothing. The U.S. spending approximately 5% of GDP on defense which while higher than the European members is still quite low. I would prefer a raise to approximately 6.5-7%.
http://img207.imageshack.**/img207/6638/heritagedefensespending.jpg
The US has a lot to spend its budget on. You really need proper health care before you need to spend more on defence. I too want a strong US military (not because I share every US cause, some of them are damnright idiotic), but because China would be worse as a world master than the US.