When Dzhokhar Tsarnaev was arrested Friday night, the celebration was instantly overtaken by an ideologically charged debate. Liberals argued that the government must respect Tsarnaev’s constitutional rights, by which they meant that he should be treated the same as any ordinary criminal suspect—informed of his Miranda rights, supplied with a lawyer, presented to court as soon as possible. The subtext was that the treatment of Tsarnaev would refute yet again the hated Bush administration’s claim that it needed expansive war powers to fight terrorists. Conservatives by contrast, notably Republican Sens. John McCain and Lindsey Graham, argued that the government should classify Tsarnaev as an enemy combatant, and thus deprive him of the rights of ordinary criminal suspects. For the left, the Tsarnaevs are examples of “vulnerable Muslims” driven to extremes by President Obama’s immoral drone war; for the right, they are foot soldiers in a civilizational war.

The Obama administration, as always, threaded the needle. The government declared that Dzhokhar Tsarnaev would not be classified as an enemy combatant, but also would not be read his Miranda rights under the administration’s broad interpretation of the “public safety” exception to the Miranda rule. The Supreme Court has recognized a relatively narrow exception, which allows into court statements made before the Miranda warning as long as an immediate threat to public safety exists (like a bomb planted somewhere). The Obama interpretation would allow in statements taken before a Miranda warning as long as the government determines the usual warning would prevent the government from obtaining “valuable and timely” intelligence.

But this needle-threading will probably not work. As Emily Bazelon explains, no court has yet approved the Obama administration’s interpretation of the public safety exception. Tsarnaev’s interrogators take the risk that a court would not allow a jury to hear statements he makes under the administrations’ broadened exception to Miranda (as I predict a court would). As Bush Attorney General John Ashcroft argues, this may not matter for Tsarnaev given the other evidence of his guilt. But it will be important for investigations of future terrorist attacks. Others have complained that Obama has jumped the gun and accused the Tsarnaevs of terrorism before it has been proved that they had terrorist motives, thus contributing to prejudice against Muslims and (one could add) undercutting Dzhokhar’s chance for a fair trial.

Read more at Slate