Britain arrests five men over a suspected attack on the airfield US bombers use against Iran

Britain has lent this runway to the US under an agreement dating from the 1950s, and the base sits about 100 miles west of London ^[4]. It keeps getting used because the runway is long enough for heavy bombers. Fairford has handled them in at least three wars: the Gulf War, the 2003 Iraq war and this year's war on Iran ^[5][16]. For most of that history the cost to the host was political. Sunday's case adds a policing cost. British police made the arrests outside a base the US Air Force operates ^[2], and US European Command said it would not discuss "specific force protection measures" ^[13].

The two accounts split on motive. Semafor reported that investigators believe a motive tied to Tehran is most likely ^[17]. Fortune reported that it is unclear whether the arrests are linked to the Iran war ^[18]. It also noted that British security officials already blame Iran-linked proxies for a string of arson and sabotage attempts in the UK and other countries, many aimed at the Jewish community, and have warned that Tehran could widen its British targets if the Middle East conflicts continue ^[10]. Anti-war campaigners have protested at Fairford's perimeter fence several times since the war started ^[7].

There are two ways this plays out, and they point to different conclusions. If charges tie the plot to Tehran, Iran's reach will have extended to the home soil of a country that stayed out of the fighting. If the case turns out to be domestic, the argument that hosting US bombers invites attack falls back on the proxy record British officials had already described ^[10]. Either way, the permission was narrow. Then-Prime Minister Keir Starmer agreed to US use of British bases for "defensive" operations against Iran's missiles and their launch sites ^[9].

The Gulf hosts have already faced Iranian strikes on US military targets and, by Semafor's account, are not questioning their strategy ^[14]. Regional powers "understand some of the challenges of having US military [bases]," the diplomatic adviser to the UAE president told Foreign Affairs, adding that the war and the Iranian attacks have made having them more important, not less ^[15].

In the adviser's account, a bigger threat raises the cost of hosting and the value of hosting at the same time. I think that transfers to Britain less cleanly than the Gulf would like, or rather, it transfers only to the part of Britain's exposure that Iran created directly. The Gulf states host US forces within reach of the Iranian strikes they have already faced ^[14]. Britain's exposure comes from lending a runway to a campaign it declined to join. The counter-case is that London has already made the Gulf's argument once. Iranian attacks on UK interests and on Britain's Gulf allies moved it from refusal to permission within days ^[8][9]. If investigators confirm a Tehran link and the government leaves that permission as it stands, the counter-case wins and the Gulf view holds outside the Gulf. For now the visible response is at the gates: local residents said security around Fairford appeared heavier in recent days, with heavy vehicles parked across the entrances ^[11].