Pakistan is likely working to create tactical nuclear weapons, which are smaller warheads built for use on battlefields rather than cities or infrastructure. These weapons are diminutive enough to be launched from warships or submarines, which makes them easier to use on short notice than traditional nuclear weapons.
Developing tactical nuclear weapons calls for miniaturization of current weaponry (the "Davy Crockett," developed by the US in the '50s, was designed to launch from a simple tripod). But as The Washington Post reports, analysts are divided on whether Pakistan will be able to make warheads tiny enough for sea-launching.
There's less uncertainty about the military advantage gained with such weapons. A warhead-toting navy would allow Pakistan to stay nuclear-capable regardless of what happens to its homeland, where its nuclear infrastructure is spread out.
The trade-off there, for both Pakistan and the world, is that nuclear missiles become more likely to fall into rogue hands, whether those of a maverick military commander or extremist groups. At a land-based facility, a hijacker would need "to commandeer two separate facilities, with two separate security procedures and local commanders," Jonah Blank, a political scientist with the RAND Corporation, wrote in an email to Business Insider. "For a sea-based nuclear device, a rogue operator would need only to commandeer one asset: A submarine or surface vessel." Other safeguards exist - US submarines, for instance, require complex codes before permitting a nuclear offensive - but faster access still simplifies one factor in a high-stake equation.
Historically, deterrence and the stability it brings is often the salutary result of rivals with equal nuclear capability. It's also Pakistan's stated goal. Last September a statement from a meeting of the National Command Authority (which directs nuclear policy and development) said Pakistan is developing "a full-spectrum deterrence capability to deter all forms of aggression." The meeting was presided by Pakistani prime minister Nawaz Sharif.
"India has what's called the triad, the ability to launch nuclear weapons form air, land, and now soon by sea. Pakistan is looking for the same," Arif Rafiq, a researcher at the Middle East Institute, told Business Insider. He believes nuclear parity between the countries has achieved deterrence. "Since India and Pakistan tested nuclear weapons in 1998, there has been a greater level of restraint in terms of the behavior of both countries when it comes to war," Rafiq said. "They've advanced their nuclear arsenal but they've also taken significant steps towards normalizing relations."
While nuclear weapons can be beneficial, Rafiq doesn't exactly applaud them: "Having one nuclear warhead is something that's terrible enough for this world," he said.