PETER HITCHENS: My secret meeting with mole at the heart of The Great Poison Gas Scandal

This is Peter Hitchens Mail on Sunday column

I stood outside the safe house, in a road I cannot name, in a major European city I cannot identify, not sure what I might find inside. I had no way of being sure. 

I had travelled a long distance by train to an address I had been given over an encrypted email.

I was nervous that the meeting might be some sort of trap. Leaks from inside arms verification organisations are very sensitive matters. Powerful people mind about them. 

I...