James Crabtree is executive director of IISS-Asia in Singapore. He is author of "The Billionaire Raj."

Leonard Glenn Francis is a giant man who left a bigger scandal in his wake. Known as "Fat Leonard," the Malaysian entrepreneur made a fortune as a U.S. Navy contractor until his 2013 arrest on bribery charges, in what is often described as the worst corruption scam in U.S. military history.

Francis charmed and cajoled sailors around Asia for more than two decades, using cash and prostitutes as bait. He "seduced the 7th Fleet," as The Washington Post put it, describing his ties to the U.S. navy's flagship force in the region. Yet nearly a decade on from his arrest, both the U.S. and other global navies still have many lessons to learn from Fat Leonard's excess -- especially as they enter a new era of maritime competition with China.

Francis is languishing quietly under house arrest, awaiting trial in California, having pled guilty to charges of overbilling the U.S. Navy by around $35 million. His case returned to the public eye earlier this month, however, with the release of a podcast by Tom Wright, examining Francis and his one-time company, Glenn Defense Marine Asia.

The co-author of "Billion Dollar Whale," a book on Malaysia's 1MBD scandal, Wright smuggled recording equipment into Francis' home. The ensuing interviews provide gripping details of how he helped the U.S. Navy refuel and restock its ships while also bilking its contracts and tempting its sailors.

At his peak, the 350-pound (160-kg) businessman lived in a $130 million mansion in Singapore, operated a fleet of nearly 200 boats and even sailed the oceans on his own personal warship, the Braveheart. Francis refurbished the ex-British military logistics vessel, packed it with Gurkha mercenaries and prostitutes, and deployed it as a floating party boat to entertain officers. "Everyone was in my pocket," as Francis said in the podcast. "I had them in the palm of my hand."

The U.S. military says it has dealt with Fat Leonard's scandals and is keen to move on. A decadelong investigation has so far put 19 servicemen in jail, including Rear Adm. Robert Gilbeau, the first U.S. Navy admiral ever to be charged with a federal crime. "I censured a vice admiral and two rear admirals and ended their careers," as former Navy Secretary Ray Mabus put it, speaking to CBS News recently.

Rear Adm. Robert Gilbeau, left, became the first U.S. Navy admiral ever to be charged with a federal crime. Cmdr. David Morales, right, was found guilty of conduct unbecoming an officer and failing to report foreign contacts on his security clearance renewal. (File photos by AP and Reuters)

Even so, there are lessons to be learned from Fat Leonard's disgrace -- beginning with the fact that the scandal may not be as over as the U.S. Navy would like.

Francis' case is winding toward trial next year, which could produce fresh evidence of wrongdoing. Many who follow the case feel justice has not been done, not least the fact that severe punishments were meted out to junior officers while senior figures got off more lightly -- a pattern ex-naval officer Blake Herzinger, now a fellow at the Pacific Forum think tank, dubs "different spanks for different ranks."

Wright argues the Fat Leonard imbroglio implies deeper structural problems than the misdeeds of a few bad apples, as the U.S. Navy often implies. One problem stems from the navy's ability to examine many allegations of wrongdoing via internal probes, rather than independent external investigators. "The question now is whether the U.S. will look more deeply into cases of culpability in this scandal, or choose to brush it under the carpet," Wright suggested.

It is also far from clear that the underlying issues of corruption in outsourcing have been fully addressed. These involve so-called husbanding contractors like Glenn Defense Marine Asia, which provide port services to navy ships from refueling and waste removal to supplies and repairs.

To be fair, the U.S. Navy has introduced major reforms to this husbanding process since the Fat Leonard scandal broke, improving tendering processes while increasing transparency, oversight and accountability. Still, ports around much of Asia remain graft-ridden places, making it hard even for scrupulous organizations to operate cleanly.

Indeed, similar scandals are all too easy to imagine in the future. Only last month, the U.S. Justice Department sought to extradite one fugitive contractor, Frank Rafaraci, head of Multinational Logistics Services, a logistics group that grew to prominence when Francis' empire collapsed.

The most important lesson from Fat Leonard, however, is that these kinds of temptations are a function not of naval weakness, but of ambition. Francis made his millions as the U.S. Navy sought to expand its operations in Asia during the 1990s and 2000s. Global militaries often seek outsourcing relationships as they ramp up operational tempo, as the scandals that engulfed the private military company Blackwater during the second Iraq War showed.

To state the obvious, navies around Asia are becoming ambitious once again. This is true of the U.S. as it rushes to keep pace with China's maritime modernization. But it is true also for many others, from Japan and India to Germany and the United Kingdom, whose new carrier strike group recently left the region after a debut deployment.

The result is what many analysts describe as a new naval arms race, and one that without careful management is all too likely to bring the temptations of graft along with it. The U.S. Navy will be delighted to see the back of Fat Leonard. But as they seek to push back against China, they and other regional militaries need to keep pushing back against the threat of corruption too.