Putin is an isolated dictator, devoid of scruple. Firing missiles into Russia will only lead to more hardship for the people of Ukraine

This is how big wars start, when small ones go wrong. Nato politicians are deliberately playing with fire along the Ukrainian frontier, as UK-made missiles have been launched into Russia for the first time since the beginning of the conflict. The attack came a day after Kyiv used US-supplied long-range weapons to strike within Russia. Every military comment on British and US authorisation of missile attacks on Russia has said the same. They are “too little, too late”, and unlikely to affect a war that has increasingly turned to Russia’s advantage.

So why are the attacks happening? The answer of Britain’s defence secretary, John Healey, is that he wants to “continue doubling down” on Britain’s support for Ukraine and give a morale boost to its president, Volodymyr Zelenskyy, before Donald Trump takes power in Washington. He clearly thinks the obvious risk involved in the escalation is worthwhile.

Simon Jenkins is a Guardian columnist