In December 1998, the US and Britain launched a three-day bombing campaign on Iraqi targets.
The previous months had seen a mounting crisis in relations between the UN weapons inspections body, Unscom, and the Iraqi regime.
Iraq had obstructed inspectors, denying them access to so-called "presidential palaces" and refusing to co-operate.
It repeatedly accused the body of spying for the US and Israel.
The UN later acknowledged that inspectors had been passing information on to US intelligence services.
In the middle of December, Unscom chief Richard Butler reported that Iraq had continued to obstruct inspectors.
Within hours, UN staff were evacuated from Baghdad and airstrikes launched.
The official aim of the cruise missile and bombing attacks on some 100 targets across Iraq was to "degrade" Saddam Hussein's ability to produce weapons of mass destruction.
As well as facilities associated with chemical and biological weapons production, the targets included sites housing the regime's secret police and elite Republican Guard forces, airfields, air defence sites and a Basra oil refinery.
Iraqi Deputy Prime Minister Tariq Aziz said 62 military personnel had been killed and 180 injured.
US President Bill Clinton faced criticism at home and abroad for undertaking military action at a time when he was under fire over his relations with White House intern Monica Lewinsky.