ANKARA

Despite the world's nine nuclear-armed countries possessing fewer warheads in 2020, they have increasingly deployed their arsenal with operational forces, according to the Stockholm International Peace Research Institute (SIPRI) 2021 yearbook.

The US, Russia, UK, France, China, India, Pakistan, Israel, and North Korea together had an estimated 13,080 nuclear weapons as of the start of this year -- down from 13,400 compared to 2020's estimates, SIPRI said in a press release on Monday.

"Despite this overall decrease, the estimated number of nuclear weapons currently deployed with operational forces increased to 3,825, from 3,720 last year," said the statement. "Around 2,000 of these -- nearly all of which belonged to Russia or the USA -- were kept in a state of high operational alert."

Though the US and Russia continued reducing their overall nuclear arms inventories by dismantling retired warheads in 2020, the institute said that both were estimated to have had around 50 more nuclear warheads in operational deployment compared to last year. The Kremlin also increased its overall military nuclear stockpile by about 180 warheads.

"The overall number of warheads in global military stockpiles now appears to be increasing, a worrisome sign that the declining trend that has characterized global nuclear arsenals since the end of the cold war has stalled," said Hans M. Kristensen, associate senior fellow with SIPRI's Nuclear Disarmament, Arms Control and Non-proliferation Program.

"The last-minute extension of New START (Strategic Arms Reduction Treaty) by Russia and the USA in February this year was a relief, but the prospects for additional bilateral nuclear arms control between the nuclear superpowers remain poor," Kristensen was quoted in the release as saying.

On Feb. 3, Russia and the US announced an extension of the New START, the Strategic Arms Reduction Treaty, for five years until Feb. 5, 2026.

The treaty is the last pillar that prevents the two nations from relapsing into a new Cold War and unleashing a full-fledged arms race as they together possess more than 90% of global nuclear weapons.

"Both Russia and the USA appear to be increasing the importance they attribute to nuclear weapons in their national security strategies," added Kristensen.

Other nuclear-armed states invest for future capabilities

The other seven nuclear-armed states are also either developing or deploying new weapon systems or have announced intentions to do so, according to the statement.

While the UK reversed its policy of reducing the country's nuclear arsenal and raised its planned ceiling for nuclear weapons from 180 to 260 in earlier 2021, China is in the process of significantly updating and expanding its nuclear inventory.

India and Pakistan also appear to be expanding their nuclear arsenals, while North Korea continues to enhance its military nuclear program as part of its national security strategy.