"Being the ambassador to Russia was probably the hardest assignment of my career," Lynne Tracy, who represented the US in Moscow from 2023 and 2025, tells the BBC.

US, UK and European diplomats once played a crucial role in Russia, defusing tensions even at the worst moments of the Cold War.

But now, deemed "unfriendly" by President Vladimir Putin's government, Western ambassadors are under constant surveillance, isolated and increasingly cut off from the country they were sent to understand, as the war in Ukraine grinds on through its fifth year.

The BBC has spoken to five diplomats who have served in Russia since it launched its full-scale invasion.

They compare current pressure levels to the Cold War era - when Western embassies were monitored through physical surveillance, listening devices hidden inside gifts , and "spy dust" - a near invisible chemical agent used to track officials.

Hundreds of Russian diplomats were expelled from countries in Europe and the US after the war began in 2022.…