The search for a shipyard willing to build, for Taiwan, eight diesel-electric submarines, continues. None of the European shipyards that specialize in this sort of thing will do it, as they fear economic retaliation from China. The United States had not built a diesel electric sub since the 1950s. Getting an American shipyard up to speed on building diesel electric subs would be expensive, and no one is sure exactly how expensive. Moreover, the uncertainty of how much it might cost is scaring many Taiwan supporters in the U.S. government. So alternative solutions are being sought. Publicly, Taiwan says it wants the subs for anti-submarine work. But its been pointed out that there are cheaper and more effective anti-sub capabilities available using helicopters, aircraft and UAVs. What is left unsaid is that the subs could also be used to shut down Chinas ports, crippling the economy and causing lots of political problems for Chinas leaders. Its also possible to shut the ports without using subs (air dropped naval mines, or just threatening to attack any merchant ship entering Chinese waters), but nothing does this sort of thing as effectively as a submarine, especially a very quiet diesel-electric sub.