To ask the Secretary of State for Defence, with reference to paragraph 3.3 of National Security Strategy and Strategic Defence Review 2015, published by the Government in November 2015, which challenges set out in that paragraph he plans to tackle by the maintenance and replacement of the Trident nuclear weapons system.
The UK nuclear deterrent has a vital role to play in the security challenges for the coming decade and beyond. It safeguards against state-sponsored nuclear terrorism; provides the ultimate insurance policy against potential Weapons of Mass Destruction threats from states to the UK and its vital interests including our NATO Allies, and helps to maintain the rules based international order.
As stated in paragraph 4.64 of the National Security Strategy and Strategic Defence and Security Review 2015, other states continue to have nuclear arsenals and there is a continuing risk of further proliferation of nuclear weapons. There is a risk that states might use their nuclear capability to threaten us, try to constrain our decision making in a crisis or sponsor nuclear terrorism. Recent changes in the international security context remind us that we cannot relax our guard. We cannot rule out further shifts, which would put us, or our NATO Allies, under grave threat.