The last major remnant of Saddam Hussein’s nuclear program  – a huge stockpile of concentrated natural uranium — reached a Canadian port Saturday to complete a secret U.S. operation that included a two-week airlift from Baghdad and a ship voyage crossing two oceans.

The removal of 550 metric tons of “yellowcake” – the seed material for higher-grade nuclear enrichment — was a significant step toward closing the books on Saddam’s nuclear legacy. It also brought relief to U.S. and Iraqi authorities who had worried the cache would reach insurgents or smugglers crossing to Iran to aid its nuclear ambitions.

Saddam was after nukes? Who knew?

…in a symbolic way, the mission linked the current attempts to stabilize Iraq with some of the high-profile claims about Saddam’s weapons capabilities in the buildup to the 2003 invasion.

Accusations that Saddam had tried to purchase more yellowcake from the African nation of Niger _ and an article by a former U.S. ambassador refuting the claims _ led to a wide-ranging probe into Washington leaks that reached high into the Bush administration.

Tuwaitha and an adjacent research facility were well known for decades as the centerpiece of Saddam’s nuclear efforts.

Israeli warplanes bombed a reactor project at the site in 1981. Later, U.N. inspectors documented and safeguarded the yellowcake, which had been stored in aging drums and containers since before the 1991 Gulf War. There was no evidence of any yellowcake dating from after 1991, the official said.

U.S. and Iraqi forces have guarded the 23,000-acre site — surrounded by huge sand berms — following a wave of looting after Saddam’s fall that included villagers toting away yellowcake storage barrels for use as drinking water cisterns.

Paging Joe Wilson, paging Joe Wilson…

The yellowcake issue also is one of the many troubling footnotes of the war for Washington.

A CIA officer, Valerie Plame, claimed her identity was leaked to journalists to retaliate against her husband, former Ambassador Joe Wilson, who wrote that he had found no evidence to support assertions that Iraq tried to buy additional yellowcake from Niger.

A federal investigation led to the conviction of I. Lewis “Scooter” Libby, Vice President Dick Cheney’s chief of staff, on charges of perjury and obstruction of justice.