Many people argue that the courts should defer to the government in time of war, because otherwise national security might be in dire peril. If the government claims that it needs to restrict individual constitutional rights or go beyond the usual bounds of separation of powers in order to defeat the enemy, perhaps judges should not scrutinize its claims too closely. After all, they are not experts on military strategy, and usually don’t have access to as much intelligence as the president and his subordinates do.
A major flaw in this argument for judicial deference in wartime is that the government’s claims about national security interests often aren’t trustworthy. As South Texas law professor Josh Blackman points out, the federal government has a long record of lying to the courts and Congress in wartime, exaggerating the extent to which infringements on the Constitution really are needed to promote national security. He gives several examples, some of them well-known, and others less so. Most notoriously, the government deceived the Supreme Court about the supposed security threat posed by Japanese-Americans in order to justify interning them in concentration camps during World War II. Sadly, as Josh notes, bad behavior of this type has continued during the War on Terror.
Given this track record, broad judicial deference during wartime is both dangerous and likely to create perverse incentives. It is dangerous because it could end up authorizing infringements on civil liberties and the separation of powers that aren’t actually necessary. Deference to government deceptions also encourages future deceptions of the same kind. If, on the other hand, courts closely scrutinize the government’s claims in such cases (if necessary, considering confidential intelligence evidence in camera), that would give the government a stronger incentive to stay honest, and reduce the incidence of unnecessary violations of civil liberties.