Commuter trains are the easiest target for terrorists, as we have seen in Madrid, London, and now Bombay. But it is difficult for a Westerner to comprehend the kind of overcrowding in a Bombay local train; they ferry six million passengers a day. A bomb that goes off in one of those compartments will have maximum impact.

If you are late for work in Mumbai and reach the station just as the train is leaving the platform, don't despair. You can run up to the packed compartments and find many hands unfolding like petals to pull you on board. And while you will probably have to hang on to the door frame with your fingertips, you are still grateful for the empathy of your fellow passengers, already packed tighter than cattle, their shirts drenched with sweat in the badly ventilated compartment. They know that your boss might yell at you or cut your pay if you miss this train.

And at the moment of contact, they do not know if the hand that is reaching for theirs belongs to a Hindu or Muslim or Christian or Brahmin or untouchable or whether you were born in this city or arrived only this morning or whether you live in Malabar Hill or New York or Jogeshwari; whether you’re from Bombay or Mumbai or New York. All they know is that you’re trying to get to the city of gold, and that’s enough. Come on board, they say. We’ll adjust.

While I was writing my book, I got a top police official in Bombay an invitation to study terrorism at the Rand Institute in Washington DC. This would have helped the city enormously, as he was the detective who cracked the '93 blasts case. But the commissioner declined to let his subordinate take up the offer from Rand, because of his fear that it was CIA-affiliated. That culture of suspicion needs to change; India needs to learn how other democracies fight terror.

Commuter trains are the easiest target for terrorists, as we have seen in Madrid, London, and now Bombay. But it is difficult for a Westerner to comprehend the kind of overcrowding in a Bombay local train; they ferry six million passengers a day. A bomb that goes off in one of those compartments will have maximum impact.

In the looking, I found the cities within me.

It was when I realised I had a new nationality: I was in exile. I am an adulterous resident: when I am in one city, I am dreaming of the other. I am an exile; citizen of the country of longing.