Now that the immediate crisis in Mumbai is over, questions and accusations are flying.
Indian authorities are pointing the finger at Pakistan and, whether the allegations prove true, the mere implication that Pakistan is at all connected to the attacks has reignited tensions between the two countries. And that, experts say, could have been the terrorists' true goal.
A senior police Indian police official told Indian media today that the only gunman captured after the deadly attacks claimed to be part of a Pakistani militant group called Lashkar-e-Taiba, whose primary cause is to win the disputed region of Kashmir, which has been a flashpoint in the two countries' relations for more than 60 years.
Indians have long believed this group has been operating as a surrogate for the Pakistani intelligence agency, the ISI. But experts say while there may have been a historical connection, that may no longer be the case.
"These groups, these Kashmiri jihad groups have at times been under Pakistani military control but not necessarily consistently. And they don't necessarily take their orders directly from them," said Bruce Hoffman, a security studies professor and terrorism expert at Georgetown University. "So you could conceivably have a case where some Kashmiri jihadi group turns out to be responsible for Mumbai but has been operating on their own."
Hoffman, who has spent years studying Lashkar-e-Taiba and other Kashmiri militant groups, said they have set their sights much broader than Kashmir and that they think of themselves as part of the larger global jihad against the West.
"Make no mistake, many of these Kashmiri Jihadi groups are as hostile to the U.S. and Israelis as they are to India," Hoffman said, adding that al Qaeda has a history of using groups like these as proxies and could be in some way involved in the Mumbai attacks.
Tom Sanderson, a senior fellow with the Center for Strategic and International Studies in Washington, said that even though it is too early to place blame, one thing is certain: It is virtually impossible for 10 terrorists to have carried out the attacks on their own.
"It was a highly sophisticated and coordinated attack with a large amount of planning," Sanderson said. "That always indicates help from somewhere else."
But the Pakistani government is denying any involvement.
"The state of Pakistan and all branches of the state of Pakistan can say with a great degree of certainty that none of us had anything to do with it," Pakistani Ambassador to U.S. Hussain Haqqani told ABC News. "I don't think it is appropriate to blame Pakistan without any evidence."
A full investigation is already under way. At least six of the more than 180 people killed in the attacks were American and the United States has sent over an investigative team from the FBI to help Indian authorities uncover the motives behind the attack and what -- if any -- larger elements were behind it.
Relations between the nuclear neighbors have been volatile since the partition that carved out Pakistan from India in 1947 and triggered the migration of millions of people, as Hindus fled Pakistan and Muslims left India.