If you would keep a secret from an enemy, tell it not to a friend.

In a shocking turn of events that has left the international diplomatic community reeling, a high-stakes security breach at the European Union's headquarters in Brussels has exposed the timeless wisdom behind the age-old adage, "If you would keep a secret from an enemy, tell it not to a friend." The incident, which has prompted a thorough overhaul of the EU's information security protocols, began with what seemed like an innocuous slip-up among allies.

According to sources close to the investigation, the breach originated from an unexpected quarter: a casual conversation between two long-time colleagues and friends, Ambassador Maria Rodriguez of Spain and Ambassador Pierre Laurent of France. Both held high clearance levels due to their involvement in the EU's Counter-Terrorism Task Force. The conversation in question took place over dinner at a discreet, upscale restaurant in Brussels' city center, a setting chosen for its privacy.

The secret in question pertained to "Operation Nightshade," a covert, multi-national operation aimed at dismantling a significant terrorist financing network spanning across Europe, the Middle East, and North Africa. Scheduled for launch in six weeks, the operation's success heavily depended on the element of surprise. Ambassador Rodriguez, having just been briefed on the operation's final details, shared the information with Ambassador Laurent under the assumption of absolute trust, given their 15-year friendship and collaborative history on sensitive projects.

Unbeknownst to Ambassador Rodriguez, Ambassador Laurent had, in recent months, been undergoing marital troubles and had found solace in a newfound, intense friendship with Natasha Petrova, a Russian diplomat stationed in Brussels. Petrova, it has since been revealed, was not just any diplomat but a highly trained officer of the SVR, Russia's foreign intelligence service. In a moment of vulnerability and perhaps seeking to impress or confide in Petrova, Ambassador Laurent inadvertently betrayed Rodriguez's trust, sharing the details of Operation Nightshade.

The repercussions were swift and devastating. Within 48 hours of the dinner, encrypted communications intercepted by NSA operatives indicated a flurry of unusual activity among the targeted terrorist network, suggestive of an imminent dispersal. By the time the EU could react, key figures had vanished, and the financial trails had been meticulously covered, rendering Operation Nightshade effectively obsolete.

The aftermath of the breach has seen a scramble for accountability. Ambassador Laurent has been recalled by the French government and is facing interrogation. Ambassador Rodriguez, though cleared of any intentional wrongdoing, has requested a temporary leave of absence, citing a personal crisis of trust. Natasha Petrova, meanwhile, has been declared persona non grata and expelled from Belgium, though her whereabouts are currently unknown.

"This incident serves as a stark reminder of the thin line between friendship and national security," stated EU Commissioner for Home Affairs, Ylva Johansson, in an emergency press conference. "We are not just enhancing our technical security measures but also reinstating and expanding our interpersonal security training programs to prevent such breaches in the future."

As the EU embarks on a period of introspection and reform, the global intelligence community is taking note, recognizing that in the arena of espionage and counter-terrorism, the boundaries of personal and professional relationships are being increasingly tested. The adage, once a mere proverb, has become a stark operational guideline: If a secret is to be kept from an enemy, the safest bet, no matter how harsh it may seem, is to withhold it from a friend, lest the line between loyalty and security become fatally blurred.

Investigative Findings and Response Highlights:

• Security Audit: An immediate, EU-wide security audit has been initiated to identify potential vulnerabilities in information sharing protocols.

• Operational Restart: Plans for Operation Nightshade are being radically revised, with a new launch date and strategy yet to be disclosed.

• Diplomatic Fallout: Russia has responded to Petrova's expulsion by recalling its ambassador to the EU for "consultations," heightening tensions.

• Training Overhaul: Mandatory workshops on "Information Security in Personal and Professional Relationships" are to be rolled out across all EU diplomatic corps and security agencies.

As the dust settles, one thing is clear: in the high-stakes game of international security, trust, even among friends, is a luxury few can afford. The challenge now lies in balancing the human need for connection with the imperative of secrecy, a delicate dance that will define the future of global cooperation and security.