There is no way to prevent 100% of such attacks from happening, but there is a way to make them look irrelevant, to undermine the undermining effect of terror.
The message from the Mumbai terrorists is : we want people to hate each other because we fundamentalists need war and hatred to survive, we want Hindis to go at Muslims, we want Jews to go at Muslims, and most of all we want moderate Muslims to be silenced and overwhelmed by fundamentalists. The masses will follow us because we will accurately claim that Muslims are once again the actual victims of the attacks.
The main target in the Mumbai attacks was Pakistan, the weaker link, and the democracy the most likely to fall for fundamentalism if the international community fails to help it help itself. Manmohan Singh must not finish the mission of the terrorists and blame Pakistan, but help fellow victim Asif Ali Zardari win over enemies from within, and together they must expose the fundamentalists' agenda which as always is only about politics, not religion.
The best way and the only way to tackle terror is to go at its roots : to recognize the existence of unfairness and to start doing something about poverty, to denounce fundamentalism as foul politics masquerading as religion, and to let the moderates speak.
The opinion should be prepared for that, and the community bracing itself through positive and sound values, and neither through fear, nor nationalism. Let's not make the same mistakes as after 9/11, please.
The terrorist attack on Mumbai clearly echoes Huntington's "Clash of Civilizations" because both are proposing the same imposture : this clash of civilizations, these religious wars are artificial, man-made, and deliberately fueled by people who want them to happen. No wonder Huntington's book is a bible for the neocons and theocons who sold the invasion of Iraq and dream of provoking a war between Israel and Iran. Fundamentalist in Chief George W. Bush offered the worst answer to the 9/11 attacks, but the best ones from the terrorists' point of view.
The worst answer to the Mumbai would be for India to retaliate against Pakistan.
Afghanistan was not guilty for 9/11 : the World let it fall into the wrong hands. Pakistan is not guilty for the Mumbai attacks : the World must prevent it from falling into the wrong hands.
The World, united, must declare its independence from fundamentalism.