Has the American military ever sneak-attacked?
The biggest example in the last 30 years was Operation Desert Storm.
Iraq conquered Kuwait, and the US and other members of the UNSC condemned the action and demanded Iraqi troops withdraw on August 1, 1990 via United Nations Security Council Resolution 660 (for the original document, see https://daccess-ods.un.org/TMP/2...).
On the 12th of August, Saddam Hussein said he would only withdraw if all other Middle Eastern powers withdrew from their occupied territories; Israel would have to withdraw from the West Bank, Gaza Strip, and Lebanon, and a few weeks later he took several British tourists hostage parading them on TV:
At the time, Iraq was a world power with the fourth largest military on earth, armed to the teeth with Soviet equipment.
The situation failed to resolve itself, and the UN passed UNSC Resolution 678 several months later (see https://daccess-ods.un.org/acces... for the original text) authorising any means necessary to force an Iraqi withdrawal, if Iraq fails to withdraw by January 15th, 1991.
On the 16th of January, the US and UK began bombing some Iraqi targets, and were later joined by most European air forces, as well as Egypt and several Near Eastern countries.
The US Navy had dispatched two carrier groups to the Gulf more than 6 months earlier, and parked a massive fleet off the coast of Iraq.
To Iraq, Russia, and China, it looked like the US was going to launch a D-Day style invasion and take 40 or 50,000 casualties securing Kuwaiti beaches. There were some analysts sitting back, surprised at how fatally flawed the perceived US plan was.
Iraq set up beach defences, and deployed almost all of its army and air defences along the Kuwaiti coast in several lines of defence starting 60 km inland, and going all the way to the coast.
They put a much less substantial defensive force along the border of Saudi Arabia.