The Open Borders Paradox holds that borders depend on extensive cross-border cooperation both for their effectiveness and legitimacy. The way Canada and the United States managed their joint land border in response to COVID-19 illustrates the extent to which functional borders are a reflection of democracy more broadly: secure and well-managed as a necessary albeit insufficient condition for openness. With the pandemic looming, both countries leveraged the binational cross-border architecture that had been built over the previous 20 years to coordinate expeditiously and proficiently to “close” the border. Yet, given the highly integrated nature of the two economies, in an effort to minimize the impact for continental prosperity, the border stayed actually open for essential traffic. The ability to calibrate the border to such an extent on so short a timeline under pressing crisis conditions demonstrates just how well managed the U.S.-Canada border is: unlike the immediate aftermath of 9/11, the border was never really closed, neither country took unilateral action, and coordination was professional and not politicized.