One of the issues that the US and EU have been arguing over is whether or not to lift the arms embargo on China, in place since the Tiananmen crackdown. The Americans oppose lifting the ban, for a number of reasons. The US government says that lifting the ban endangers Taiwan. This doesn't hold a lot of water - China is still buying tons of weaponry from Russia and Israel, including the Su-27 and Su-30, which have already outflown the F-15 in Indian-US war games. So protecting Taiwan is already impossible, unless the US brings Taiwan into the Joint Strike Fighter program, as Taipei has requested.
I don't think you have to be a scholar to guess that the US is more concerned about the long-term position of the Chinese military. But the problem here is what the US can actually do to prevent this - even if the arms embargo isn't lifted, China will still be able to buy some pretty decent gear from the Israelis and Russia, so overall China's stature is going to grow, no matter what.
Anyway, China is still a few years away from realistically able to "take" Taiwan, but even once they have the capability, they're unlikely to pull that trigger. There's so much that can go wrong in that scenario, and Beijing has to know that.