What about the US' ability to attack everyone? How about those pricks disarm and reduce their military to 1/10th the size, stop toppling governments because they don't like them etc?
You're mixing up capability with likelihood. Total risk is the product of the two. The U.S. has had nuclear-capable ICBMs for over 50 years now, but has never used them. So while it has had the capability for a long time, the proven likelihood that it'll use them is very low, even when it's been provoked. The reason people (not just the U.S.) is concerned about North Korea's capability is because its leadership is extremely erratic and unpredictable, so the likelihood it would actually use ICBMs is a lot higher than existing nuclear powers'.
Also, U.S. military spending is huge only if you look at it in raw dollars. That's like looking at the raw dollars a large wealthy household spends on food, and comparing it to what a homeless individual spends. If you insist on looking at it in raw dollars, we could divide U.S. military spending across all 50 states (many of them are larger than most countries) and *poof* - the individual states no longer have the world's largest military spending.
The proper normalized metric is spending (any type, not just military) as a percent of GDP. That eliminates the effect of wealth and population. Basically, what percentage of your citizens' productivity do you direct to your military? By that measure, U.S. military spending is about 3.5% of its GDP. That's only about 1.5x the world average of ~2.3% of GDP. By that measure, the U.S. doesn't even make the top 25 in military spending. And that's not even factoring in Japan, which the U.S. is contractually obligated to defend by the terms of peace treaties signed ending WWII. Include Japan's GDP and U.S. military spending drops to about 2.7% of aggregate GDP. If you cut U.S. military spending to 1/10th what it is now, it would have just about the lowest military spending of any nation on earth.
Incidentally, guess which country spends the most on its military as a percentage of GDP.