Again. I certainly hope that this isn't true.
EDIT: The second tweet. Don't know how to isolate it.
Sushko said they were supposed to launch the attack at 5 - 5:30 AM and it's currently a little after 6 AM in Ukraine now.
It's possible there was something planned, but they backed off when there were leaks, or it may just be rumor blown out of proportion. We don't know.
Using Kaliber's for a nuclear strike is risky, the Ukrainians have gotten pretty good at shooting down cruise missiles. The toughest thing to shoot down would be ballistic missiles. Russia has a lot of Iskander launchers gathering dust and most experts assume Russia held back a few Iskander missiles for use with nukes if Russia decides to use them.
Is this a credible source?
He doesn't seem to be worried.
Theiner is pretty credible. His track record is better than Sushko's.
Yeah, Nukes in Ukraine would be just about the stupidest thing Russia could possibly do, with the exception of striking NATO.
It would result in short order of:
1) China cutting them off completely, for fear of being in any way (economically, politically) related to what was about to happen to them
2) Being completely cut off economically from the world - the west would go beyond sanctions, we would be talking blockades of ships transiting to/from Russia
3) the mother of all airstrikes on any Russian ship in the Black Sea (this was already warned to Russia if they used nukes)
4) the arming to the teeth of Ukraine with everything in the west's conventional arsenal (M1A1s by the thousands, F16s by the hundreds, ATCAMS, cruise missiles, you name it). Plethora of weapons not only able to allow Ukraine to fend off Russian aggression, but to take the fight to Russian territory.
Did I miss anything?
China and India are both downwind if nukes are used and both may shut off Russia if they use a nuke. Putin did back down on his talk of nuclear weapons after he spoke with Xi Jingping. Xi may have made it clear that China would not tolerate Russia using nuclear weapons.
China is not giving direct military aid to Russia, but they are indirectly selling them the materials they need to make weapons and ammunition. If China cuts them off, Russia will run out of the chemicals needed to make ammunition and the electronics to make the weapons they are making.
If Russia uses nuclear weapons, the US might get involved in the war, at least using air assets. The US would probably not put boots on the ground, Ukraine has enough ground forces to do the job. I could see the US imposing a no fly zone over all pre-2014 Ukrainian territory and possibly extending it to anything flying near their territory which appears to be armed. As part of the no fly zone, all Russian anti-air assets would be removed from the board too.
I saw somewhere someone say that Biden told Putin they he would give nuclear weapons to Ukraine if Russia used one. I kind of doubt that considering how paranoid the US is about their nuclear weapons and keeping tight control on them, but it would be poetic justice.
The world would likely rally around Ukraine in the aftermath of a nuclear attack like the world rallied around the US after 9/11.