I AGREE with Richard Rowles (Letters 23 March) that we need to send a strong message asserting that we will not tolerate the release of chemical weapons on our territory.

The difficulty, though, is establishing to whom this message should be directed.

There could be many explanations for the Novichok incident.

The predictable consequence of this debacle is increasing tension between the west and the Russian Federation so it is worth considering who would benefit from such an outcome.

There is no death penalty in the Russian Federation for treason but the Russians had Skripol in prison for a number of years and then released him in a spy swop.

Why they should choose to kill him years later seems odd.

Leaving a “calling card” of a nerve agent originally produced in the USSR is even more curious at a time when they are both trying to showcase the Russian Federation at the World Cup and get sanctions lifted.

Until there is a full, thorough and independent investigation we will not know the truth. Even then, the truth could be elusive. Novichok was identified as the agent in this incident. According to the Organisation for the Prohibition of Chemical Weapons protocols, the accused state should be sent a sample for analysis and given ten days to respond.

We did not do this which was a mistake and undermines both our credibility and our international standing. Not following due process led to the tragic Iraq debacle which cost countless lives.

We should not forget the lessons of history!

Maureen Treadwell, Chilbolton.