It is not only in the United States that a debate has started about whether Putin is still sane.
One thesis says that the self-imposed shielding he put himself into during the pandemic made the Russian president even more ruthless, hurt and suspicious than before.
In the end, it's just reading tea leaves, because nobody in the West is Putin's psychologist.
But we also know from other countries that politicians miscalculate their wars.
The goal is deterrence
The nuclear threats that Putin is making when he raises the alert need not be a sign of a lack of rationality either.
Nuclear powers have repeatedly threatened their opponents with nuclear strikes.
Just think of the dispute between Trump and Kim Jong-un a few years ago.
As a rule, this is intended to achieve deterrence.
In the case of Putin, the message is addressed to NATO.
This can be seen not only from his statements (if one can still believe them), but also from the fact that the alarm concerns the so-called triad, i.e. the ground, air and naval forces.
That would not be necessary to intimidate Ukraine.
Putin is probably primarily concerned with a threatening gesture towards the United States.
It reads: Stay out of it, otherwise I'll escalate.
This will primarily be meant in a military sense, but he is apparently also reacting to Western sanctions.
risk of misunderstandings
Under the current circumstances, this is a highly negligent aggravation of the situation.
It makes a limited regional war, in which NATO is not involved, a potential confrontation between the two nuclear superpowers.
A higher alert level unnecessarily increases the risk of misunderstandings or accidental kills.
Putin is now turning the bad enough conventional raid on Ukraine into a high-risk nuclear gamble as well.
It's good that the American government didn't follow suit immediately.
At least one side should take a moderate stance, just as the West is not taking part in the fighting in Ukraine with soldiers.
In principle, America and Europe are well advised to rely on their own nuclear deterrence.
The "mutually assured destruction" of the Cold War still applies.
Putin faces a devastating retaliation against Russia should he seriously plan to attack the United States or any other NATO country with nuclear weapons.
So far this has had an effect.
The federal government began a long-overdue turnaround in security and defense policy over the weekend.
This includes the nuclear question, even if it will be particularly difficult for the Germans.
Half a century ago, Germany renounced nuclear armament when it joined the Nuclear Non-Proliferation Treaty.
That could not be changed overnight, either politically or in terms of armaments technology.
However, Macron's offer of cooperation in this area should be accepted as a matter of urgency, provided it is still valid after the elections in France.