USA, UK, Russia, France, China had hundreds to thousands of Weapons of Mass Destruction (Nuclear devices). Israel also had over hundred such WMDs unannounced though.
When India tested her Nuclear Device objections were raised by the Western powers but there was not much of fuss. Finding threat of WMDs at door and then blatant warnings by Indian leaders including that by India’s
Prime Minister, Pakistan decided test Nuclear device.
Pakistan informed the big powers and neighbouring countries about the test to be performed. Hell broke and threats and warnings started pouring in from USA and UK as if all the earlier WMDs of seven countries together were roses and if Pakistan tested the device, perhaps, skies will collapse. After the test, stringent embargos were slapped on Pakistan.
Now North Korea, being under threat of the Western powers, has tested a nuclear device and skies appear to be falling again. All sorts of embargos have been slapped on North Korea through UNO.
No body ever asked Israel why she had about 200 of Nuclear WMDs without ever announcing even the capability to produce one.
No body questions who has used Nuclear devices so far (at Hiroshima and Nagasaki)? No body asks who used dilapidated Uranium in Afghanistan and Iraq. That all, perhaps, was showers of roses.
U. S. A. : More than 5,000 strategic warheads, more than 1,000 operational tactical weapons meant for the battlefield and less powerful than the strategic arms and approximately 3,000 reserve and tactical warheads.
Russia: Nearly 5,000 strategic warheads, and approximately 3,500 operational tactical warheads. In addition, it has more than 11,000 strategic and tactical warheads in storage.
France: Approximately 350 strategic warheads.
China: As many as 250 strategic warheads and 150 tactical warheads. U.K. : About 200 strategic warheads.
Israel: Refuses to confirm it is a nuclear weapons state but is generally assumed to have up to 200 nuclear warheads.
India: Between 45 and 95 nuclear warheads.
Pakistan: Between 30 and 50 nuclear warheads.
North Korea: Believed to have enough fissile material for about a half-dozen weapons, but estimates vary widely and are unverifiable.