The "alleged terrorist" attacks in Mumbai raise the issue of how to interrogate terrorists captured in the middle of an operation, when information may save innocent lives. In the longer term, the rules governing terrorist interrogation and detention may decide whether the terrorists live or die, but not for the reasons you think.
The Indian government did not have to take the terrorists captive. In the heat of a battle, it would have been just as easy for an Indian commando to get off one last burst of fire, and dispatch a terrorist with extreme prejudice. No one would have known the difference. But there was an incentive not to do so. That incentive was the opportunity to interrogate the terrorist to obtain actionable information. Take away the ability to engage in meaningful interrogation, and you have removed an important incentive to take a terrorist captive.
In the war with terrorists, the United States faces a similar dilemma. Currently, there is a strong incentive for the US to capture rather than kill terrorist suspects, in order to obtain information regarding terrorist plans and structure. Rather than dropping a bomb on a house, it is in the US national interest whenever possible to send troops into the house to capture the targets. The intelligence benefits from these efforts are mostly secret, but what has leaked out shows that the capture rather than killing of terrorists has benefited the US effort against terrorism. Sometimes, such as in areas of Pakistan, this is not possible, and a missile fired from a drone is the only alternative.
Removing the incentive to take terrorists captive may have an unintended consequence of leading to more terrorist deaths. The closing of the Guantanamo Bay detention camp (Gitmo), and providing terrorists captured abroad with the full panoply of US constitutional rights, makes this unintended consequence more likely.
The history and litigation regarding Gitmo are well known. Numerous cases have worked their way to the US Supreme Court and other federal courts regarding the rights of Gitmo detainees. These cases have largely upheld Bush administration policies, while providing prisoners a path to the US judiciary in limited form. Barack Obama has repeated his pledge to close Gitmo, although he has not revealed what he would do with the residents.
How broadly closing Gitmo changes the incentive to capture rather than kill terrorists depends upon what the alternative looks like. If the alternative is the application of domestic evidentiary and judicial standards to suspected terrorists captured on the battlefield, as some have advocated, then there is no incentive to take captives. The levels and burdens of proof required in a domestic criminal trial are so great that almost no suspect captured on the battlefield will be convicted. Prosecutors have enough trouble convicting suspects picked up on the streets of Chicago; there will be little likelihood of convicting suspects picked up on the streets of Helmund Province.
There are a lot of issues involved in the Gitmo detainee cases, and I don't mean to suggest that anything goes with captives. But those arguing against any form of coercive interrogation, or who want to make it nearly impossible to convict terrorist captives, should understand the law of unintended consequences.