A Putin victory would be a green light for tyrants everywhere

It is now almost three years since Russia outraged international law and decency in a barbaric, lawless invasion of its neighbour, Ukraine. For the first time since 1945, Europe was convulsed and disfigured by devastating conventional war.

The world's main fear is, of course, a nuclear conflict, which would end everything. But the misery created by non-nuclear combat is terrible.

We have seen massacres, streams of refugees forced from their homes by terror, and appalling destruction of cities. 

Uncounted numbers of young men have been killed, maimed or disfigured. Whole stretches of countryside have been turned into churned-up, uninhabitable desolation.

The people of Ukraine have also had to endure the privations of war, and ever-worsening reductions of the electric power necessary to maintain modern civilisation. And yet they have not given up.

A new state, born less than 34 years ago out of the collapse of the Soviet Union and still taking shape, has been hardened by battle and suffering into a self-conscious, deeply patriotic nation. 

President Volodymyr Zelensky has borne himself with dignity and courage, never flinching from a hard task forced upon him by events. Let us not forget that he came from outside Ukraine's political class, and that his original platform was one of peace, not war.

Russia, meanwhile, has sunk deeper into a grim autocracy. President Vladimir Putin has never even admitted that his 'Special Military Operation' is an invasion, and has almost entirely stamped out free speech as he persecutes any who dare to oppose him. 

His armed forces have inflicted a great deal of damage and loss, but they have also suffered terrible casualties, as many crammed new cemeteries in Russia testify.

So what are we to do now? Britain's role has from the start been important. We have armed, aided and encouraged Ukraine in its battle to fight off its far larger, far richer and far more ruthless neighbour. 

Some of our military equipment has been highly effective on land and sea in destroying key parts of the Putin war machine. But by ourselves we cannot supply all the needs of Kyiv.

What we can do, as a pillar of Nato and as the USA's oldest and most reliable friend, is to urge our American and European allies to stay in the fight. We should strongly advocate their continuing and powerful support to ensure that Putin does not get away with his brutal, expansionist adventure.

In The Mail on Sunday today, a highly experienced military and political figure, Sir Iain Duncan Smith, says bluntly that Ukraine is fighting with one arm tied behind its back.

Sir Iain, a Sandhurst-trained former Army officer, knows what he is talking about. On a recent visit he noticed that front-line Ukrainian troops were having to improvise with antique British equipment dating from half a century ago.

Sir Iain correctly points out that American interest has recently shifted to other theatres of war, especially Taiwan and Israel. 

But he also says a Western failure in Ukraine would increase the danger in both these places. Aggressive tyrants all over the world are waiting to see the outcome. They would be hugely encouraged by a Putin triumph.

Much depends on the attitude taken by the newly re-elected US President Donald Trump, who once said he could end the Ukraine war in 24 hours. It seems that he is not so sure now.

Britain should be doing all it can to persuade him that Ukraine's struggle for independence and freedom is worth fighting and winning.