Responsible Statecraft has reported:

A former British diplomat says UK counter-terrorism police detained him for three hours on the night of Oct. 2 after he arrived on a flight from Moscow via Istanbul. He was questioned under the Counter-Terrorism and Border Security Act 2026 after telling an officer he had attended a geopolitics conference in Russia, and says police searched him and his belongings, took his fingerprints and DNA, and required him to surrender his electronic devices and passwords on pain of arrest.

He describes the detention as “suspicionless,” saying he was not suspected of an offence but was subject to an examination intended to determine whether he was planning a “hostile act” against the United Kingdom. He says he was not told a reason for being held beyond the officer’s statement that he wanted to ask him “a few questions.” The officer also told him the counter-terrorism powers “aren’t as scary as they sound.”

The former diplomat attended the International Valdai Discussion Club Conference in Moscow Region from Sept. 27 to Oct. 1, including Russian President Vladimir Putin’s keynote address. He says the Valdai Club invited him and provided his flights and accommodation, a standard arrangement for foreign guests at such international conferences.

He says he informed the UK Foreign Office before travelling, following advice from former British ambassador to Russia Sir Tony Brenton, whom he had consulted. Brenton described Valdai as an “excellent event.” The former diplomat says he told the Foreign Office he would meet his obligations under the Official Secrets Act and confirmed that, although Valdai paid for his flights, he received no payment for attending.

He served as a British diplomat for 24 years and retired in 2023. During a four-and-a-half-year posting in Russia that ended in February 2019, he worked as Economic Counsellor, with responsibilities that included sanctions policy. After returning to the UK, he authorized around 1,000 sanctions against Russians, including after the war began.

Before travelling to Moscow for the conference, he was concerned that his role in sanctions could cause problems in Russia. He says he was subjected to a “four-and-a-half-hour detention and interrogation by the FSB upon arrival in Moscow.” The article does not identify him by name.

The Valdai Club was founded in 2004 and is described as a gathering attended primarily by academics from around the world. Before Russia’s invasion of Ukraine, participants included a former head of MI6, Brenton and Fiona Hill.

The author says Valdai has come under scrutiny from the British government. Throughout September, he writes, journalists and academics received letters from the UK Home Office inviting them to register with the Foreign Influence Registration Scheme if they were “being directed to carry out relevant activities in the UK as part of an arrangement with a foreign power.” Failure to comply with the scheme is a criminal offence.

British journalist Mary Dejevsky, a publicly listed Valdai Discussion Club contributor, was the latest to receive such a letter, according to the article. Dejevsky was The Times bureau chief in Moscow in the 1990s, but has not attended Valdai since the war began. The former diplomat calls the suggestion that conference attendance means someone is directed by a foreign power “patently absurd,” while saying the possibility of consequences made him consider whether to accept the invitation. It was his first visit to Russia since he drove out in February 2019 at the end of his diplomatic posting.

He says he takes seriously his continuing duty to protect secrets he encountered during his 24 years in diplomatic service. He calls the suggestion that he might plan a hostile act against Britain “offensive and wrong.” Since retiring, he has publicly criticized the direction of UK foreign policy towards Russia, particularly what he describes as a shift away from diplomacy and towards war.

The former diplomat says the precautions he took did not stop him from being detained with fewer rights than he would have had if formally arrested and cautioned. He believes security officials in London authorized the action in advance. Russia commentator Mark Galeotti suggested on his podcast that the system was “making a statement” by acting in this way.

The article says a request for comment from the UK’s Counter Terrorism Policing went unanswered as of publication. The author supplied documentation of his detention to Responsible Statecraft, which made the request.

He places the airport detention within what he calls a growing pattern of pressure on people who publicly oppose “forever wars” in Ukraine, the Middle East and elsewhere. He argues that people who criticize Western foreign policy are increasingly treated as national security threats. Airport detentions, he writes, fall short of imprisonment, but he says intimidation has spread over the past four years.

The article lists several previous detentions. Conservative British academic and author John Laughland was held at an airport for one hour in 2022. In 2023, the late Robert Skidelsky, a House of Lords member and British economist, and investigative reporter Kit Klarenberg faced longer and more rigorous detentions. Klarenberg has not received back an SD memory card taken at the time.

Professor Richard Sakwa, emeritus at Kent University, was detained for three hours at Heathrow in 2025. The article says he was able to return to Russia only after his lawyer intervened. Hungarian-born British political analyst George Szamuely said he was detained in March 2026.

Craig Murray, a former British ambassador to Uzbekistan, was detained for an hour at Glasgow Airport in 2023 under tougher provisions of the Terrorism Act 2000. The act concerns activity related to the commission, preparation and instigation of terrorist acts. Murray’s phone was not returned to him afterwards.

Investigative journalist Richard Medhurst was arrested over statements supporting a proscribed pro-Palestine organization and held for 24 hours before release. In February 2025, his home and office in Austria were raided, and he was accused of membership in Hamas. No charges have been laid against him to date, the article says.

The author also points to the proscription of Palestine Action as a terrorist organization in Britain following widespread protests against what he calls gross violations of international humanitarian law by the Israeli state in Gaza. He says elderly demonstrators, including Holocaust survivors, have been arrested at Palestine Action protests for holding cardboard placards.

The article says suspicionless airport detention is uncommon in European states, while other forms of repression are used. Jacques Baud, a former Swiss military intelligence officer and author, remains in Brussels, unable to travel home and “de-banked,” after the European Union sanctioned him for “pro-Russian propaganda.”

It also says Russian-born journalist and former BBC reporter Leonid Ragozin was declared persona non grata by Latvia in the past week. He has lived there since the onset of the Ukraine crisis and has criticized Western policy on the war. The article notes that Ragozin has also regularly criticized Putin and described Russia’s 2022 invasion of Ukraine as “criminal and irrational.”

The former diplomat fears that British state actions may become harsher as it becomes clearer, in his view, that the West cannot win the war in Ukraine and Israel cannot avoid international censure over its actions in Palestine. He warns that offering an opinion on what he calls the perilous state of Western foreign wars could lead to prison, and says his case suggests no one is safe from what he calls lawfare if a former diplomat can be detained and have property temporarily confiscated.

After returning from Valdai, he wrote again to the Foreign Office and offered to brief officials fully on what he learned in Russia. He says the office has not replied.