Putin’s ‘unbeatable’ nuclear-powered missile has several serious drawbacks

“As demonstrated by several test failures, it is a very complex and thus error-prone means of delivering a nuclear payload,” said Dr Sidharth Kaushal, senior research fellow at the Royal United Services Institute, a London-based think tank. He said the missile “may be viewed as a bargaining chip”, with Moscow hoping to include it in negotiations over the New Start treaty, a deal capping the number of deployed nuclear warheads, which is set to expire in February next year.