If the goal was to decouple from China then tarrifs would only be on China and we would encourage trade to move from China to other countries. The administrations actions have the opposite effect. It says the US is untrustworthy even to it's allies and maybe siding with China is not so bad. Note I don't like or trust the Chinese government and don't think other governments should try to get closer to them but Trump's actions make such moves much more likely