Vladimir Putin’s brutal attack on his Ukrainian neighbors has sparked global outrage — and forged unprecedented unity — among the democratic nations of the world. Not so with Xi Jinping, the hypernationalist president of the People’s Republic of China. Rather, he is no doubt taking notes and learning lessons from Russia’s unprovoked attack on Ukraine to apply to his plans for Taiwan.

The United States and our partners in the international community need to do the same to develop and put in place a new and more resilient strategy for Taiwan while there is still time.

A clear lesson from the war in Ukraine is that authoritarian leaders have been emboldened in recent years by dysfunctional democracies and hesitant international institutions. Accordingly, the United States needs less ambiguity to guide our approach to Taiwan. In today’s world — with Mr. Xi’s China — a robust and credible deterrence to preserve peace and stability across the Taiwan Strait requires clarity in word and deed. President Biden vowed in May to use force to defend Taiwan — the third time he has said so, even though his aides have said the longstanding U.S. policy of strategic ambiguity has not changed.

The moral and strategic case for standing with Taiwan, whose people share our interests and our values, could not be clearer. China is carrying out influence campaigns against Taiwan using cyberattacks and disinformation, deploying propaganda to reinforce its “one China” message, spreading disinformation and conspiracy theories to divide Taiwanese society and make it easier to gain control of the island. This is a plan of attack eerily reminiscent of Mr. Putin’s in Ukraine.