Is the United States a dangerous country?For people in other countries, the United States is extremely dangerous--if you choose to wage war or otherwise threaten its security or the security of one of its allies. It can project enormous military power at any spot on the globe in a matter of hours, sometimes less, if it needs to. But if you don't do either of these things, it's quite harmless. In fact, it hands out more aid to foreign countries than any other nation in the world, and is quite willing to assist if a natural disaster strikes another country. The USA doesn't like going to war, but since December 7, 1941, it's had a very pro-active foreign policy with regards to the rest of the world, and even more so since September 11, 2001.
Internally, living in the USA is also very safe. Stories about gun violence and other unrest here are common in the media, both here and abroad, but in the context of a population of 321.4 million people, the third largest in the world behind China and India, those are isolated incidents. The United States keeps its crime rate under control by having an incarceration policy that is stricter than probably any other democratic state in the world; it's well-known that the USA has the largest acknowledged (that's a key point in understanding this statistic) prison population in the world.
Parents overprotect their kids because that's what good parents do, in the United States or any other country of the world. There are messed-up people who are dangerous to children everywhere, not just in the United States. You just hear more about it here because of our very open and diverse media, and its tendency toward sensationalism, not to mention that in a population of more than 300 million people, of course you'll have more unstable and predatory people than a smaller nation would.