As tactical nuclear arsenals are modernised, the risk of arms-racing grows

President Obama had a line in his speech at Hiroshima earlier this year that really zeros in on one of the themes of the modern nuclear era.

After describing World War II and the destruction caused by the bombings at Hiroshima and Nagaskai, the President said: 'Science allows us to communicate across the seas and fly above the clouds, to cure disease and understand the cosmos, but those same discoveries can be turned into ever more efficient killing machines.'

In a new Lowy Institute Analysis, I argue that as the major nuclear powers Russia, the US and China continue to modernise their nuclear forces, technological advancement is making one element of their nuclear arsenals more precise and sophisticated: tactical nuclear weapons.

Tactical nuclear weapons are those intended for battlefield purposes and they generally possess low-yield nuclear warheads. More precise and capable versions of these weapons can strengthen deterrence. Theoretically they make nuclear arsenals more robust and dynamic, lending credibility to deterrence and help prevent conflict. But they also make nuclear weapons more 'useable' against a greater variety of targets and in a wider range of scenarios. This could harm strategic stability and eventually encourage arms races.

Two technological trends are influencing the way tactical nuclear weapons could impact strategic stability: the proliferation of precision strike weapons and the emergence of advance area-denial capabilities and credible ballistic missile defence. [fold]

In terms of precision strike weapons, the US demonstrated the effectiveness of the 'reconnaissance-strike complex' during the first Gulf War. Post-war assessments noted that there was a 'qualitative' shift in the effectiveness of precision guided weapons during the conflict. This is largely due to the integration of sensors, receivers and satellite positioning and tracking systems, like GPS, into air-dropped munitions and cruise missiles.

The demonstration of Washington's 'reconnaissance-strike complex' was a shock in Moscow and Beijing, and both countries have invested deeply over the years in similar capabilities. Over the last several years, it has become increasingly clear they have made significant progress.

The result of Russia's military modernisation was fully demonstrated in Syria in late 2015. The Russian Navy's cruise missile strikes from surface vessels and submarines in the Caspian and Mediterranean Seas showed significant improvement in Russia's ability to conduct long-range precision strikes. This was likely enabled largely due to the revitalisation of Russia's indigenous GPS equivalent, GLONASS. Importantly, these strikes were carried out with the new nuclear-capable Kalibr cruise missile.

China has been making similar advances. Beijing has been building an increasingly capable regional intelligence, surveillance and reconnaissance infrastructure, including over the horizon radars and passive electronic surveillance systems. This is paired with China's own GPS-type system, the BeiDou satellite constellation, which received its 23rd satellite in June. When combined, these capabilities will allow the PLA the ability to conduct coordinated and precise strikes from a multitude of ballistic and cruise missiles within the region. While there is scant evidence that China has invested in tactical nuclear warheads or plans to, its ability to use nuclear weapons within the region in a limited fashion if it chose to has improved.

The proliferation of these systems and their potential impact on strategic stability has not been fully considered. One way these capabilities could upset stability is by blurring the distinction between conventional and nuclear use. Another is the prospect that 'decapitation strikes', a source of Soviet anxiety during the Cold War, could become more feasible. Indeed, there are some indications that nuclear-capable, submarine-borne cruise missiles are playing a role in nuclear dynamics between Russia and the US in a similar way.

Other technology that may be under-appreciated in terms of their effect on the modernisation of tactical nuclear arsenals is the development of anti-access/area-denial (A2/AD) capabilities and credible ballistic missile defences. As the US debates the future of its nuclear modernisation efforts, the Pentagon has used the A2/AD 'challenge' as a reason for the necessary modernisation of US nuclear-capable cruise missiles. Indeed, the Pentagon sees A2/AD systems as a threat to its ability to control and maintain escalation superiority if deterrence fails. Likewise, US investment in credible ballistic missile defences is playing a role in an evolving action-reaction dynamic concerning Russia and China's modernising nuclear arsenals.

The biggest risk going forward is that the nuclear modernisation programs of the major nuclear powers, particularly in regards to precise tactical nuclear weapons, become 'interactive'. As was the case during the Cold War, a cycle of improvement and investment in nuclear arsenals could develop, where countries can fear 'being placed at a disadvantage in crises or a breakdown of deterrence.' As Michael Krepon and Julia Thompson have written, this can lead to nuclear arsenals more 'suited for war-fighting than deterrence' and can result in fostering arms race dynamics.

Nuclear use among the major nuclear powers remains highly unlikely. But technology can shift the way states consider tactical nuclear weapons in the future. The international community has a role in calling for greater transparency around these types of weapons.

Photo: Getty Images/Handout

Brendan Thomas-Noone