A relieved Katharine Gun, 29, walked free from the Old Bailey criminal court in London on Wednesday after prosecutors said - without elaboration - that they would be offering no evidence against her.
"I am absolutely overwhelmed and I am obviously delighted," she told reporters outside the court, where a supporter gave her tulips. "I am just gobsmacked, just speechless."
Asked if she would leak a similar memo again, the blonde whistleblower replied: "I have no regrets and I would do it again, yes."
Gun, a Chinese speaker sacked in June from her job at the
Government Communications Headquarters (GCHQ), was charged in November under the Official Secrets Act 1989 of disclosing security and intelligence information.
She was accused of disclosing a request from the US National
Security Agency for help from British intelligence to eavesdrop on non-aligned UN Security Council delegations in the run-up to the Iraq war.
The US memo - details of which emerged in the Observer newspaper - was sent to British authorities at the time when Washington and London were seeking a UN Security Council resolution to green-light their invasion of Iraq.
Angola, Bulgaria, Cameroon, Chile, Guinea and Pakistan were the UN Security Council members named in the memo as targets of the eavesdropping effort, which Gun feared would have been illegal.
Mounting a surge
The memo - reprinted by the British Sunday paper on 2 March - was signed by Frank Koza, defence chief of staff (regional targets) at the National Security Agency.
The memo was directed at
UN Security Council members
He explained that the agency was "mounting a surge particularly directed at UN Security Council members ... re: Iraq."
It was interested, he said, in "the whole gamut of information that could give US policymakers an edge in obtaining results favourable to US goals or to head off surprises".
In court on Wednesday, prosecutor Mark Ellison said his team
would not offer evidence against Gun "as there is no longer
sufficient evidence for a realistic prospect of conviction".
"It would not be appropriate to go into the reasons for this
decision," he said.
"I am absolutely overwhelmed and I am obviously delighted. I am just gobsmacked, just speechless"
But Gun's lawyers and Liberty, the human rights group that championed her case, were left frustrated by the mystery surrounding the prosecution's decision to abandon their case.
"Why have they waited until today?" asked Barry Hugill, a spokesman for Liberty, outside the court. "Why has she been put through eight months of hell?"
Gun, who studied Chinese in Taiwan and taught in Japan before joining GCHQ, had previously said that "any disclosures were justified because they exposed illegality by the US, who tried to subvert our security services".
Gun's defence was likely to have proven embarrassing and possibly damaging for the British government.
She intended to ask Lord Goldsmith to publish his full advice to the government declaring the legality of waging war against Iraq, something the UK's chief government law lord has so far refused to do.