Thank you for your letter of 12 May on why the UK has been able to accede to the Ottawa Convention while the US believes its holdings of landmines make its ratification of the Convention impossible.

  It is true that the UK's anti-tank mines, some of which have anti-handling devices, fall outside the definitions in the Ottawa Convention which you quote. Anti-handling devices are a necessary component of our mines, designed to ensure that mines cannot be quickly removed, so that they achieve their function of delaying an enemy advance. Our understanding is that the US has adopted a different approach to protecting its anti-tank and anti-vehicle landmines, using mixed mine systems which involve mixing anti-personnel mines, as defined under the Ottawa Convetion, with anti-tank mines to slow mine clearance by an enemy. The cost and difficulty of modifying existing mines means that the Americans have said they need to retain anti-personnel mines for this role.

  They have also pointed to the specific difficult circumstances they face in Korea as a reason for retaining anti-personnel mines. There is the potential in Korea for attack by numerically superior forces with very little warning time, which is no longer the case for NATO forces in Europe. Anti-personnel mines form a significant component of US and South Korean fixed defences.

  The US has indicated its intention of signing the Ottawa Convention by 2006, which we welcome, but this is conditional on an effective alternative to anti-personnel mines can be found. To this end, they are pursuing a number of avenues of research, with a substantial programme budget of over $900 million. As yet, we understand that no alternative to anti-personnel landmines has been found which meets the US criteria of military sufficiency, cost-effectiveness, and minimising risks to non-combatants, but they believe that some of their approaches have the potential to find an alterative to anti-personnel mines.