While the political risks are huge, that does not necessarily preclude an attack (though I certainly agree that US media at this time is quite over-hyping the danger of an imminent attack on Taiwan). To reach for a hackneyed but nonetheless applicable example, the political risks to Hitler of remilitarizing the Rhineland and annexing the Sudentenland were immense, as a forceful military response from the UK and France would likely have resulted in his fall from power at either domestic or foreign hands, and yet he rolled the dice anyways.

Given that, as Bill observed the other day, Xi appears to be a "true believer", I hesitate to underestimate the degree to which he might be willing to take an action which appears dangerous yet harbors immense ideological and reputational value for him if successful.