First, he promised to end the Russian invasion of Ukraine “on day one”. Then, after being elected President of the United States, he said it would take “six months”.

The war has reached a critical point. A real peace seems unlikely, but a ceasefire is possible, most experts agree. The question is whether it can be achieved without placing Ukraine in further peril.

Putin has said repeatedly that he is prepared to negotiate an end to the war, which first began in 2014, but that Ukraine would have to accept the reality of Russian territorial gains, which are currently about 20% of its land. He also refuses to accept Ukraine joining Nato, the military alliance of Western countries.