Unlike some of the countries above, the United States works hard to ensure international security and stability. Countries who do not launch unprovoked attacks against other countries, often for the purpose of land or material gain of some kind, have nothing to fear from the USA or its Allies. But countries that support terrorism or more importantly have invaded and attack 4 neighbors in the past 20 years are international outlaws and need to be brought to justice somehow. US pre-emption is done to protect lives and international security, it is a defensive action. But Pre-emption or attacks done to kill civilians are annex another country is clearly unjustified, these are not defensive actions.
One of the only ways to stop terrorist in the act of committing terrorism is to act before they do. Acting after the event has happened is to late. No one wants to loose 3,025 people in the space of 2 hours like we did on 9/11. One of the best ways to prevent a 9/11 is to act before terrorist do, which may sometimes involve largescale military pre-emptive attacks. If a country does not want to be the target of a military pre-emptive strike, don't support terrorist and allow international forces to help you in siezing them on your soil if the country is unable to accomplish that itself. Also do not attempt to annex other countries that border your own or launch missiles at countries beyond your borders for no reason at all.