Vladimir Putin's closest advisers appeared perturbed when he dropped his bombshell about readying nuclear weapons yesterday. 'The only reason his forces face a threat today is because they invaded a sovereign country, and one without nuclear weapons.' Globally, the overall inventory of nuclear weapons is declining, but the pace of reductions has been slowing compared with the past 30 years. Russia has claimed its most potent nuclear missile, the 16,000mph hypersonic 'Satan-2', can fit 12 nuclear warheads and could destroy the UK. 'This is an attempt at deterrence by Putin, not a statement he has any immediate intention to use nuclear weapons.