The capture of Boston Marathon bomber Dzhokhar Tsarnaev sparked a debate about whether he should be charged as an American citizen (which he is) or as an "enemy combatant." If it's the latter, he presumably could be interrogated by whatever "enhanced" methods are deemed to be most effective — methods that could not be legally used on an American citizen charged with a crime, no matter how heinous.
Dzhokhar's older brother, Tamerlan, was not an American citizen and had possible connections with radical Islamacists in Chechnya, so it appears that there was a political motive behind the bombings on his part.
Dzhokhar Tsarnaev apparently shared those beliefs at some level, but as a teenager, it's possible he was manipulated by his brother. He may have even been a minor when his indoctrination began. As an enemy combatant, he'd be subject to interrogation by federal agents behind closed doors. His only defense would be how well he could stand up to whatever physical and psychological techniques were used.
Timothy McVeigh, who bombed the Oklahoma City federal building and killed 168 people, in what was no doubt an act of terrorism, was tried as a U.S. citizen, though you could argue the case that he was an enemy combatant of the U.S. and was a member of an organization dedicated to bringing down the government. I'm sure federal agents and law enforcement officials would have been delighted to have been able to waterboard McVeigh into a confession without a pesky attorney around. But we did it the right way, and the system worked. McVeigh was tried, convicted, and executed. His accomplices were also caught and convicted.
Those who favored classifying Dzhokhar Tsanaev as an enemy combatant did so mainly because they thought we'd get better information on his possible terrorist group ties by using enhanced interrogation. But what if he had no terrorist ties, just a controlling big brother who did? Is it worth torturing an American citizen to find out, no matter how horrific his crime? I don't think so, and thankfully, neither does this administration.
I believe the police and the FBI have done excellent work in solving this case and bringing the accused to face justice. Similarly, Dzhokhar's terrorist connections, if any, will be thoroughly investigated. We should let the American justice system finish the job. If we stoop to torture and ignore the Constitution whenever it seems expedient, it jeopardizes every American's right to a fair trial.
And if that happens, then, well, yeah, the terrorists win.