Why do they worry about Pakistan's nuclear weapons?

Nuclear Safety

Published in Khaleej Times on  February 11, 2011

With reference to Jonathan Power’s article ‘Beijing not much of a nuisance militarily’ (KT, Feb10), I wonder why he (and many others) are so deeply worried about Pakistan having nuclear weapons.

The US and Russia have thousands of nuclear warheads, enough to destroy the entire planet many times over, and yet no one thinks that these are vulnerable to theft or misuse. The probability of nuclear weapons falling into the wrong hands or being launched accidentally is much greater in the US than other nuclear-weapons states.

Shakir Lakhani, 

Pakistan