President Biden has wrapped up his visit to Poland with a remarkably strident call for Vladimir Putin’s removal. While the Kremlin has retorted that the Russian President’s future is not for the American President to decide, Mr Biden has let it be known that “for God’s sake, this man can’t remain in power”.

Across the world, this must rank as an eyebrow-raising comment of one Head of State against another. Historically, the stricture is almost exceptional. In the course of his visit to Poland ~ the biggest recipient of Ukrainian refugees ~ Mr Biden had also called his Russian counterpart ‘a butcher’.

The US President’s performance in the Polish capital ~ one that has been criticised by even his Republican rivals back home ~ could arguably embolden the Russian leader who ordered the invasion of Ukraine. Mr Biden took the stage in Warsaw on Saturday evening to deliver one of the most consequential speeches of his presidency, evoking Ronald Reagan among the Cold War foes of Soviet domination and warning the world to gear up for a long battle in the fight for Ukraine against Putin.

Mr Biden’s remark represents a rare call by an American President for another leader’s removal. Several White House officials quickly attempted to airbrush the comments, saying they did not seek Mr Putin’s ouster. Yet Mr Biden’s tone redefines the stakes of the conflict, and potentially fuels Russian propaganda, which has sought to justify the attack on Ukraine with claims of a need to respond to Nato aggression.

“A dictator bent on rebuilding an empire will never erase a people’s love for liberty,” Mr Biden said. “Brutality will never grind down their will to be free. Ukraine will never be a victory for Russia, for free people refuse to live in a world of hopelessness and darkness.” Indeed, hopelessness and darkness now plague Mariupol, the eastern city in Ukraine which has been largely demolished by Russian forces.

The daily insults of Mr Putin have narrowed the window of opportunity for normalising dialogue, much needed now, a point underscored by a key European ally. France’s President Emmanuel Macron was quick to remind the West that it should not use harsh words to escalate tensions. Without question, Mr. Biden’s improvised finale to his speech marks an escalation during an otherwise closely choreographed trip designed to showcase unity among Nato and European allies without tipping the geopolitical scales.

Mr Putin now joins the ranks of Nicolas Maduro, Bashar al-Assad, and Saddam Hussein as leaders who American Presidents openly wanted out of office. What makes the situation more charged is that Mr Putin is at the helm of a nuclear-armed major power in the middle of an invasion. That presents a different calculus, especially given the concerns among US officials about what the Russian leader may be capable of when pushed.

While the West has sought to project to the world that Mr Putin is increasingly being cornered, the intemperance of Mr Biden’s remarks suggests even he is facing the heat, domestically and globally.