Alien Island

the long version

Earth had not been attacked–no, indeed–and the Visitors were not about to allow the Establishment to intervene between them and the man-in-the-street. The Establishment had, in fact, been spending considerable time, energy and (taxpayers') money on an effort to shield the tender, hyper-sensitive feelings of the public from the panic it assumed would result were it ever to become generally known that the Earth had Visitors–and had been having them for several years. It was, of course, the Establishment which was scared witless. So they were bypassed. And there wasn't a thing the united governments of the Earth could do about it. Except for their unitedly witless Secret Services...