Story highlights Steven L. Hall: Intense cooperation between allied security services helps prevent terror attacks at home and abroad

It is breathtaking when the President of the United States undermines these key intelligence relationships, he writes

Steven L. Hall retired from the Central Intelligence Agency in 2015 after 30 years of running and managing intelligence operations in Eurasia and Latin America. He finished his career as a member of the Senior Intelligence Service, the small cadre of officers who are the senior-most leaders of the CIA's Clandestine Service. The views expressed in this commentary are his own.

(CNN) On March 22, at the doorstep of Parliament in London, an ISIS-inspired attacker killed a British police officer and several innocent bystanders, at a time when the British Prime Minister, Theresa May, was inside addressing members of Parliament. The attack occurred on the anniversary of the ISIS attacks in Brussels a year earlier and made one thing quite clear: Europe is still vulnerable to terrorist plots.

For every successful terrorist attack that spectacularly makes the news, scores, if not hundreds, are thwarted by the efforts of intelligence and law enforcement organizations, often working with international partners. These go largely unreported, of course, because they are not really news; the dog simply did not bark.

Steven L. Hall

What also goes unreported is the intense, constant cooperation between allied security services as they undertake the unenviable and herculean task of stopping the next terrorist operation. For the most part, intelligence and law enforcement work behind the scenes, drawing on counterterrorism liaison relationships they have built over the past 20 years, or sometimes longer. These relationships are probably the single greatest defense the West has against terrorist attacks.

So it is literally breathtaking when the President of the United States, which has the largest and best-funded intelligence community in the free world, undermines these key intelligence relationships that keep not only the United States but its allies as safe as possible.

The most egregious example of late was President Trump's fantastical claim that the British signals intelligence agency, GCHQ (London's NSA equivalent) had agreed to a request from then-President Obama to monitor the electronic communications of the Trump campaign during last year's presidential election. A clearly angry GCHQ and the British government immediately denied and dismissed the ridiculous and obviously political claim.

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