I have two answers, which will certainly qualify because you may well never have heard of either.
The first, and my primary answer because it is a local matter that the Third Culture can hope to affect, is the closing of the High Flux Beam Reactor at Brookhaven National Lab.
Many high profile media scientists proclaimed the Supercollider decision as the point at which the US definitively turned away from science. But it was nothing of the sort. It was a badly managed and unwisely promulgated project, immensely expensive and disconnected with the rest of science, about which many perfectly reasonable scientists had serious doubts — not just me, though I seem to have taken the brunt of the blame.
My nominee for this turning point is the HFBR. A coalition of pseudo-environmentalists and trendy New Agers, useful and wellheeled Clinton friends and campaign contributors with Long Island real estate, blew up a leakage which amounted to the amount of tritium in the exit signs of your local movie theatre into a major issue, and Bill Richardson, the Secretary of Energy, caved without listening to the scientists involved. It is reported that the coalition arranged an interview for the Secretary with a supermodel on the afternoon the scientists had asked for a last appeal.
In any case the loss of the HFBR closes one of the world's most productive scientific instruments and sends the entire community off to our friendly competitors in Europe and Japan. Neutron scattering and diffraction is central to much of condensed matter physics and useful in biology, chemistry and several branches of technology. Approximately 300 experiments were run the last year the HFBR was up. There was no conceivable economic reason for shutting it down — it was a very inexpensive instrument relative to the projects which are replacing it. Its real problem is the anti-intellectual bias of the majority culture. If only we had been able to label it "organic" rather than "nuclear" it would have survived.
I will be brief about the other.
You will never have heard the name "Eppawala". This is a project of a US-Japan consortium to mine phosphate in gigantic quantities from a mountain in Sri Lanka, destroying a thousand-year-old irrigation system, numerous antiquities, and many villages and compensating the locals on a typical Third World scale with a minute fraction of the profits — profits which hardly exist if one were to count the true cost of the project. It is a staggering example of the misuse of economic reasoning which characterizes third world "development" projects. Not just third world, in my opinion!