@Walter Hinteler,
President Putin insists Russia does not want war and is ready to negotiate, agreeing with France to intensify diplomatic efforts.
But if his demands for
"security guarantees" are not met, he has threatened "appropriate retaliatory military-technical measures".
Why is Russia threatening Ukraine?
Russia has long resisted Ukraine's move towards European institutions, both Nato and the EU. Its core demand now is for the West to guarantee Ukraine will not join Nato, a defensive alliance of 30 countries.
Ukraine shares borders with both the EU and Russia. As a former Soviet republic it has deep social and cultural ties with Russia, and Russian is widely spoken there, but ever since Russia invaded in 2014 those relations have frayed.
When Ukrainians deposed their pro-Russian president in early 2014, Russia annexed Ukraine's southern Crimean peninsula and backed separatists who captured large swathes of eastern Ukraine. The rebels have fought the Ukrainian military ever since in a conflict that has claimed more than 14,000 lives.
Russia has complained that a 2015 Minsk peace deal for eastern Ukraine is far from being fulfilled. But it also accused of being part of the lingering conflict.
What does Putin want?
Russia has spoken of a "moment of truth" in recasting its relationship with Nato and has highlighted three demands.
First, it wants a legally binding pledge that Nato does not expand further: "For us it's absolutely mandatory to ensure Ukraine never, ever becomes a member of Nato," said Deputy Foreign Minister Sergei Ryabkov.
Mr Putin has complained Russia has "nowhere further to retreat to - do they think we'll just sit idly by?"
Last year President Putin wrote a long piece describing Russians and Ukrainians as "one nation". He has described the collapse of the Soviet Union in December 1991 as the "disintegration of historical Russia" and considers Ukraine's current leaders as running an "anti-Russian project".
President Putin has also argued that if Ukraine joined Nato, the alliance might try to recapture Crimea.
Its other core demands are that Nato does not deploy "strike weapons near Russia's borders", and that it removes forces and military infrastructure from member states that joined the alliance from 1997.
That means Central Europe, Eastern Europe and the Baltics.
In reality Russia wants Nato to return to its pre-1997 borders.
The whole article is here:
https://www.bbc.com/news/world-europe-56720589