It’s becoming increasingly clear that the Paris massacre will reopen debates about security and surveillance—which, since the Snowden revelations and related events, appeared to be breaking in favor of privacy advocates—in a big way. New York City Police Commissioner William Bratton said yesterday that encryption technology was likely “a significant factor” in the attacks, and this morning took a shot at Silicon Valley software manufacturers, who he said are “working against us” by failing to create back doors for law enforcement to monitor suspected terrorists’ communications. CIA Director John Brennan made similar comments at a CSIS forum this morning, according to Foreign Policy‘s John Hudson. “When asked why #Paris happened, CIA Director Brennan says privacy advocates have undermined the ability of spies to monitor terrorists”, Hudson tweeted.In the coming days and weeks, we can expect intelligence officials to spar with civil libertarians over the extent to which the new privacy measures prompted by the Snowden revelations—like end-to-end data encryption software—are responsible for the attacks. But however that debate plays out, it seems safe to say that the slaughter in the City of Lights will at least dent the celebrity of Snowden and other privacy advocates like him, and make his admirers’ dire warnings about the existential threat to liberty posed by the NSA seem overblown.In periods of relative safety, Americans tend to be sympathetic to the Jeffersonian tradition—that is, zealously protective of their civil liberties and alert to the danger of creeping federal tyranny. But in periods of perceived danger, the Jacksonian impulse to get the bad guys at all costs grows more powerful.Since the Snowden leaks, America has been enjoying a Jeffersonian moment—skeptical of foreign interventions, and especially conscious of potential threats to liberty at home, like NSA snooping and militarized police forces. This moment may have already on its way out in the last year, as evidenced by Sen. Rand Paul’s decline in popularity and influence. But after Paris, it certainly is. We are once again in a period of perceived danger, for the Paris attacks, perhaps more than any other event in the last decade, highlight that the West is still at war with a vicious enemy. To many Americans, government spies and cops with big guns might no longer seem like the greatest threat to American liberty, but rather a necessary if unpleasant precaution against those who would destroy it entirely.As these debates reopen, hard-core Jeffersonians and Jacksonians alike will insist that any deviation from their preferred position will lead to either tyranny or chaos. But it is important to remember that America has a 300 year tradition of balancing civil liberties, government power, and security through a mix of legislation, judicial oversight, and public debate. While our system isn’t perfect, we have mostly reached compromises that accommodate both of these deeply American political traditions relatively well. Post-Paris, the terms of the debate have changed, but that capacity for balancing opposing values likely has not.