Most are protected by the NATO/ US nuclear umbrella. Britain has no need to possess its own nuclear deterrent. It is not Pakistan, North Korea or Israel with an agenda for territorial expansion or colonisation or illegal settlements.
Unlike the three states above, Britain is a NATO signatory to the nuclear Non Proliferation Treaty (NPT) and the International Atomic Energy Agency (IAEA) of the United Nations.
Whilst the primary duty of any government is the protection of the state – that does not require a nuclear arsenal of weapons of mass destruction.
The answer is to conform to the principle objectives of the NPT and to work to rid the world of nuclear weapons of mass destruction as agreed by all of its signatories.
The first step would be to declare the Middle East a Nuclear Weapons Free Zone to include both Israel and Iran.