The resignation of former Libyan Foreign Minister Moussa Koussa came as Libyan leader Muammar Gaddafi struggles with a do-or-die situation facing continuous airstrikes by a West-led coalition.

Koussa flew into Britain from Tunisia on Wednesday night, and told the British authorities that he was resigning his post in Libya.

Vague reaction

A day later, Libyan government spokesman Mussa Ibrahim said Koussa had asked for permission to rest because he was very ill, and the resignation was a "personal issue."

The vague remarks were followed by Gaddafi's son Saif's unyielding words on Tuesday that Koussa was "sick and old" and he had no feeling of being betrayed after Koussa's defection.

However, many in the West saw Koussa's departure as a sign that Gaddafi's inner circle was crumbling, as Koussa, previously deemed as a strongman, could make many more to follow suit. Koussa was the government's highest-ranking member to quit so far.

"Koussa's defection and the subsequent lifting of sanctions against him should encourage others within the Libyan government to make similar decisions to abandon the Gaddafi regime," said David S. Cohen, acting under secretary of the U.S. Treasury for terrorism and financial intelligence, after Washington decided Monday to lift the sanctions and asset freeze against Koussa.

Before Koussa, Libya's justice and interior ministers have resigned early in the domestic strife and joined the rebellion based in the east. Other senior officials including Libya's permanent representative to the United Nations have also quit their posts.

Defection instigated

It is widely considered that Koussa's resignation was firstly an outcome of the West-led coalition's efforts to instigate defections among the high-level officials in Tripoli as they simultaneously resort to military actions against Gaddafi's forces.

And as Libya's top intelligence official for 15 years before becoming foreign minister in 2009, Koussa could have had a good deal of close interactions with the intelligence counterparts in Western countries.

Upon his arrival, the BBC said Koussa came to London on a British military plane.

Later, reports by the British newspaper Sunday Express said the former Libyan top diplomat had once worked for the British intelligence department. Meanwhile, The Mail on Sunday, a sister paper of the Daily Mail, said Koussa "has been offered asylum in the UK in return for his help to topple Gaddafi and his hated regime."

Loosened watch

The departure of Koussa, meanwhile, was also a consequence of Gaddafi's slackened control over his subordinates amid strong airstrikes.

Sources in Libya told Xinhua that the country's senior officials were once concentrated in Gaddafi's compound in Bab Al-Aziziya in Tripoli, in isolation from the outside world.

But after the anti-Gaddafi raids kicked off over two weeks ago and the compound was hit by a cruise missile in a night bombing, Gaddafi and his children fled the place and changed residence from time to time. This might have left loopholes for those like Koussa to get away, a source said.

For the moment, whether Koussa's departure will create a domino effect or lead to even more radical changes in the situation in Libya remains unclear. But concerning Libya's political framework, the North African nation is still well in the hand of Gaddafi and his family, despite Koussa's key position in the government which was merely on operational level.