Speaking at St. Andrews University in Scotland this week, the chief of Britain's Secret Intelligence Service, commonly known as MI6, publicly confirmed one of Britain and America's greatest counterterrorism successes of recent memory: disrupting major Islamic State directed attacks on European soil.

Alex Younger, or "C" as SIS chiefs are traditionally known, noted that over the past two years British intelligence services have "disrupted multiple serious Daesh attack plans originating overseas that, if successful, would have caused significant loss of life." Younger continued, "This includes an important contribution to helping European countries, particularly our French and German allies, prevent terrorist attacks in their countries or against their citizens."

Younger is referring to European plots planned by ISIS operations officers in Syria and involving urban assaults with explosives and firearms. Here, think of the November 2015 Paris plot, which would likely have been bloodier if not for U.S.-U.K. intelligence. While Younger noted that these successes have involved SIS infiltration of ISIS, boutique efforts from the U.S. National Security Agency and Britain's Government Communications Headquarters were also crucial.

None of this should be taken for granted. Describing his effort to "delegate assertively," Younger hinted at his broader reforms to boost the intelligence service's efficiency and effect — something now-Secretary of State Mike Pompeo also did during his time leading CIA. The challenge for a human intelligence service such as SIS is that although delegation offers greater reward, it also entails greater human risk.

Younger also pointed out that SIS is heavily focused on Russia. The Russian intelligence agency GRU's attempted assassination of Sergei Skripal earlier this year proved that the Russians retain a reflex for aggression. Younger explained that this fits in a broader Russian strategy to "exploit ambiguity" in NATO defense doctrine. And while the post-Skripal attack expulsion of numerous Russian intelligence officers has hurt the Kremlin, Russian intelligence infrastructure in Britain remains significant.

Ultimately, Younger's speech reminds us why the U.S.-U.K. special relationship is so important. While Younger and his CIA counterpart Gina Haspel have a strong personal relationship, their primary strength is the values-interests binding of the Anglo-American alliance. Sourced in shared values and sustained by trust — incidentally, why President Trump has kept classified certain British intelligence related to Russia's 2016 election interference — the world is safer thanks to these spies.