When opponents of Barack Obama, the US senator who is considering a run for the presidency in 2008, turned to the internet to back up a claim that a school the Illinois senator attended in Indonesia was a radical madrasa, it did not take long to scotch the claim.

But while the mud did not stick, the four years the Democrat spent in the world's most populous Muslim nation were formative and left a deep impression on the candidate, according to his own writings and to interviews with Indonesians who knew him. Mr Obama, now 45, followed his mother, Ann Dunham, to Jakarta when he was six years old in 1967 after she remarried, to an Indonesian engineering student, Lolo Soetoro.