The reason this attack might not have been stopped by ANY country

Since there are no pilots in the flying vehicles radical shifts can be done regarding altitude and left right banking turns without making pilots sick or killing them. As a result these drones and cruise missiles can literally fly at 10 to 100 feet above the ground which makes them basically invisible to radar, and invisible to satellites (especially in the dark of night if there is no moon). So, this technology literally could surprise any country not expecting it, especially at night, even the U.S.

This is why people are worried about nuclear powered cruise missiles with unlimited range being presently developed by Russia which would also have a nuclear payload. There would be no warning and suddenly a U.S. or other city would be gone and that's all she wrote. However, it's also important to know that we are prepared for this in that we have deep hardened nuclear proof facilities in the center of our country away from the oceans. Because nuclear weapons could also be used to create 1000 foot high tsunamis that could wipe out the whole west, east or south coast in one wave or a series of tsunamis.

However, there is a big difference between what it is possible to do and what will actually happen based upon created deterrents like Doomsday weapons which the U.S. and China and Russia all have that would literally wipe all life off from earth if anyone did any of these things to the largest countries on earth.