UN helicopter strikes on rocket launchers used by Ivory Coast rogue leader Laurent Gbagbo were a stunning warning to any strongman to beware of the ominous words “all necessary measures” in a UN Security Council resolution.

After the international air assaults launched in Libya, the innocuous little phrase set up UN forces, alongside French helicopters, to stage the most daring urban warfare operation yet by international peacekeepers in Abidjan.

UN officials say more attacks against Gbagbo, who refuses to hand power to internationally recognized president Alassane Ouattara, are planned.

The military capability of Moamer Kadhafi in Libya and Gbagbo in Ivory Coast have taken a severe beating from the strikes. In each case, the 15-nation Security Council agreed to allow “all necessary measures” to protect civilians rather than sign up for regime change.

“It should be a warning. In UN Security Council-speak ‘all necessary measures’ means military action,” explained Mark Quarterman, a specialist on conflict and crisis for the Center for Strategic and International Studies in Washington and a former UN political advisor.

The same term was used to set up no-fly zones over Iraq in the early 1990s and to help peacekeepers in East Timor as deadly conflict erupted after the territory voted for independence from Indonesia in 1999.

The Abidjan offensive was rare but not unprecedented.

Peacekeepers have already had to go on the attack in Bosnia and Somalia in the 1990s and in East Timor to keep troublemakers in check.

Western nations had been pressing the UN mission to get tougher with Gbagbo for several weeks.

UN helicopters targeted the Agban and Akuedo military camps where M-21 rocket launchers are based, UN peacekeeping chief Alain Le Roy told reporters. He said French helicopters went for launchers believed to be near the Presidential palace and Gbagbo residence.

The Security Council unanimously passed a resolution last Wednesday authorizing “all necessary means” to put “heavy weapons” threatening civilians in Ivory Coast out of action. But the UN said Gbagbo had since escalated attacks.

Mr Le Roy said the UN base in Abidjan had come under “almost continuous attack for three days.” When he telephoned the UN special envoy, Choi Yong-Jin, on Friday and Saturday he was hiding in the basement of the hotel headquarters because of mortar attacks.

UN secretary general Ban Ki-moon asked France’s President Nicolas Sarkozy on Sunday to add his forces to a military assault and plans were made within hours.

While China, Russia and others still oppose the air strikes in Libya, no doubts have been expressed about the Ivory Coast action. Le Roy said after briefing the Security Council on Monday night that no voices of opposition had been raised by any of the 15 ambassadors.

Mr Ban has strongly denied that the attacks signified the UN was taking sides in the conflict between Mr Gbagbo and Mr Ouattara, who now seems to have the upper hand as his forces surround Abidjan.

“No we are shooting at heavy weapons, we are not shooting at the presidency, we are shooting where the heavy weapons are,” Mr Le Roy declared.

He acknowledged that the attacks are an “extraordinary move” but insisted: “The political backing of the Security Council was very clear. It was a clear mandate to tackle the question of heavy weapons that were attacking civilians and peacekeepers.”

Quarterman, at the Centre for Strategic and International Studies, said it could be part of a trend that the UN leader says is pushing back the frontiers of humanitarian law to protect civilians in conflict.

“This is not a genie that can be put back in the bottle,” he commented.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.