https://www.gatestoneinstitute.org/21156/taiwan-ukraine-survival
[T[he United States has an obligation to defend Ukraine — and it is definitely in its interest to do so.
In the Budapest Memorandum, the three parties [the US, the UK and Russia] made six pledges to the former Soviet republic, the most important of which was “their commitment to Ukraine, in accordance with the principles of the CSCE Final Act, to respect the independence and sovereignty and the existing borders of Ukraine.”
“[W]hen negotiating the security assurances, U.S. officials told their Ukrainian counterparts that, were Russia to violate them, the United States would take a strong interest and respond.” — Steven Pifer, former U.S. ambassador to Ukraine.
If Russia keeps the territory it has seized — certainly if it grabs even more — countries will believe that American promises to defend them are worthless and will begin building a nuclear deterrent of their own.
Russian President Vladimir Putin, after all, will not stop there, just as he did not stop after breaking apart Georgia in 2008 or after seizing Crimea in 2014. “If Ukraine falls, Poland, the Baltic republics and other NATO member states will face existential threats,” Greg Scarlatoiu, president of the Committee for Human Rights in North Korea, told this publication. Then, the U.S. and its NATO partners will be even more stretched — and less able to defend Taiwan — than they are now.
When Chinese leaders saw Washington’s failure to act, they soon moved against Second Thomas Shoal and other Philippine reefs in the South China Sea, went after Japan’s islets in the East China Sea, and started reclaiming and militarizing features in the Spratly Island chain. Obama and Biden legitimized the worst elements in the Chinese political system by showing everybody else that aggression worked.
The best way to stop China from attacking Taiwan is to defeat its proxies, especially Russia in Europe.
As Tsai Ing-wen, who stepped down as Taiwan’s president in May, said on November 23, “A Ukrainian victory will serve as the most effective deterrence against future aggression.”