A new era of US Navy nukes begins

FULLER VERSION OF MY TIMES STORY TODAY: A US Navy ballistic-missile submarine armed with new controversial “low-yield”, mini-nuke warheads is now on patrol for the first time, a senior Pentagon official has confirmed. The USS Tennessee, an Ohio-class submarine, one of 12 in the US Navy, represents what the Trump administration describes as a new “tailored” form of deterrence, aimed at warning off every potential adversary, from Russia and China at one end of the spectrum to Iran, North Korea and nuclear terrorists at the other. The plan to put smaller warheads on some of the ballistic missiles in the “boomers”, as the submarines are called, was announced in the 2018 nuclear posture review. It led to criticism from arms-control experts and some Democrats in Congress that the US would be lowering the nuclear threshold by envisaging a warfighting role for these weapons. However, the Pentagon warned that with Russia and China expanding their nuclear forces, and would-be nuclear weapons states emerging, the president needed greater flexibility to counter the burgeoning threats. “There is no one-size-fits-all” for deterrence, the Pentagon said. In confirming the first submarine deployment of the smaller warhead, John Rood, under-secretary of defence for policy, denied that it lowered the nuclear threshold. He said in an interview with AP that the new weapon would increase the effectiveness of deterrence. The US already has low-yield tactical nuclear bombs which can be carried by aircraft, including the new F-35 joint strike fighter. Critics of the new submarine-carrying warhead say it’s unnecessary and adds to the notion of a “usable” nuclear weapon. However, Mr Rood said the submarine-launched low-yield warhead would be perceived by potential adversaries as a weapon “more capable of penetrating air defences than an aircraft-launched bomb”, thus strengthening deterrence and “raising the nuclear threshold”. The USS Tennessee normally carries 20 Trident II D-5 ballistic missiles each fitted with four-to-five 90-kiloton W76-1 warheads or 475-kiloton W-88 warheads. The submarine is part of the US triad of strategic nuclear weapons – the other two parts being land-based and air-launched - which pose the ultimate threat of annihilation. The Trident missile has a range of more than 7,500 miles. This means at least two of the 20 missiles on board will still have the same range but with less destructive power. All the Ohio-class submarines are now expected to deploy with the additional new smaller warhead, called W76-2 which has an estimated yield of five-to-seven kilotons. This is one third of the size of the nuclear bomb dropped by the US on Hiroshima on August 6 1945 which flattened the Japanese city and killed 70,000 instantly, although the death toll doubled. The first deployment of the limited-kiloton warhead is part of the Pentagon’s revised defence strategy focused on the competing capabilities of Russia and China. The W76-2, adapted from the much bigger W76 and W76-1, cost $19.6 million. Apart from developing new nuclear missiles, both Russia and China are investing in hypersonic glide vehicles that can carry nuclear or conventional warheads over immense ranges. Russia is also working on an intercontinental nuclear-armed undersea autonomous torpedo. While the US is trying to catch up with hypersonic weapons, the Pentagon, under orders from President Trump, has been moving ahead as rapidly as possible in updating America’s nuclear systems. Flexibility has been a key element of the US nuclear strategy for 60 years. But now it is seen in Washington as even more important because of the diversity of nuclear and non-nuclear strategic threats in an increasingly dangerous and unpredictable world. The mini-nuke warheads fitted to the long-range missiles on board the boomers are the latest evidence of the updated strategy.