Joseph Rotblat, UK

The tragic events of Black Tuesday, with the horrendous loss of so many innocent lives, is a shocking reminder of how far we still are from the goal of a peaceful world. The existence of a powerful group of terrorists capable of executing such a dastardly act, with the likely support of some States, is a reflection of the lack of respect for accepted norms of morality.

There is the need for a universal convention to ban the harbouring of terrorist groups within a State. But in the first instance, all States should adhere to international treaties and fulfill commitments, even if they transcend national interests.