CIMSEC – This campaign analysis seeks to determine how long U.S. decision-makers can realistically have debates about intervening in a Taiwan crisis before the PLA seizes Taipei and the window for effective intervention with military force has closed. It does so by employing analytical modeling, informed by historical data, to determine how long the Taiwanese can resist a Chinese invasion absent direct U.S. military intervention given best-case-scenario timelines for the PLA. That is to say in this campaign analysis, tactical and operational chance favors the PLA, and Taiwanese resistance is more similar to that of the brave but desperate 2014 Ukrainian military fighting in the Donbass than the more successful and combat credible 2022 Ukrainian military which halted a Russian invasion. What follows is not meant to be predictive, but rather cautionary, and presents the most stressing timeline for U.S. decision-makers. Any deviations from this scenario would only serve to elongate the timeline for the PLA’s campaign, thereby increasing the decision-making space for U.S. leadership.