One Tactical Nuke Equals US no more

There is a temptation to think that using tactical nukes in Ukraine, or in Russia would result in the cessation of hostilities by Russia in Ukraine.
The most likely scenario is that the United States would cease to exist, as would Russia.
Unfortunately, the US public is not being informed about the danger of continuing the war in Ukraine, nor the current events because of social media censorship.

Putin has so far:
- Given nuclear strike capability to North Korea.
- Placed a nuclear submarine in Cuba.
- Done joint flights with China near US airspace in Alaska.
- Given nuclear weapons to Belarus

Notification was given by Putin, before many if not all of these actions were taken. The intent of the notification appears to be to avoid expansion of the war, and to persuade the US and Nato to enter into negotiation. The deployment of nuclear deterrent to Belarus was for example notified (from memory) roughly 6 months in advance.

The US government is very focussed on reaching the internal elections so that the Democrat party maybe elected. But due to terminating experts in Russian culture, and the reluctance of military advisors to provide technical information that is not convenient, they overlook the importance of the following.

(1) Long range missile strikes into Russia to delay the collapse of Ukraine until after the US November elections are indistinguishable to Russia from nuclear missile strikes.

(2) If Russia is attacked with long range, potentially nuclear, missiles then Russia will destroy British and US military bases to indicate that this type of action is unacceptable.

(3) If a tactical nuclear weapon is used in Ukraine. Russia will retaliate with all its nuclear weapons against Europe and the United States. It considers both to be party to the conflict, based on their economic expenditure on weapons.

In view of the high likelihood of long range weapons being used, the Russian diplomat says, it is VERY likely that the US will become involved in the Ukraine war.
There seems to be only one course of events that can lead to this outcome.

(a) The US authorises long range strikes into Russia.
(b) Russia can't distinguish these missiles from nuclear weapons.
(c) To stop the delivery of long range missiles that are nuclear capable, Russia reaches for a missile deterrent by expanding the war to Europe and the US using conventional means.