Editor's note: The following is an opinion piece by Duncan L. Hunter, a former Republican U.S. congressman from California.

Hunter, who served in Congress from 1981 to 2009 and as the chairman of the House Armed Services Committee from 2003-2007, is the author of "Victory in Iraq: How America Won." 

When Gen.eral John Kelly walked out of his change of command ceremony at U.S. Southern Command on Jan. 14, ending his 45 year career in tour with the U.S. Marine Corps, America lost a valuable asset. Kelly is an "old hand," one of those senior officers who understands the long war in which America is engaged. 

If Napoleon made his generals "out of mud," then our commanders were fashioned out of the desert sands of the Middle East. Kelly's combat tours spanned the entire Iraq War.   
 
When the 1st First Marine Division broke across the Kuwait border in 2003 on its lightning strike to Baghdad, Iraq, Kelly was deputy division commander to Gen. general James Mattis. As Mattis' "wagon boss," Kelly kept the regimental combat teams moving through Saddam Hussein's divisions. Always, Kelly's judgment was superb. 
 
As mentioned in my book, when the opportunity to slaughter defeated Iraqi soldiers arose, Kelly instructed his officers that the mission was to take Baghdad, not "kill a lot of mothers’ sons." Sent north with Task  Force Tripoli after Baghdad's fall to receive the surrender of senior Iraqi officers, Kelly responded to an Iraqi general's surrender of his pistol by giving the surprised Iraqi his own pistol. "The war is over" was Kelly's message. "Time to rebuild." 
 
As the war entered the long slog of occupation, Kelly understood the need to pivot from conventional warfare to counterinsurgency. Driving the wedge between the tribes of Iraq's Anbar province and al Qaeda, the Marines, while engaging in fierce firefights, worked to bring water, electricity and medicine to the tribes. In the end, due to the genius of America's desert warriors, Marines and Army soldiers, the tribes came over to the U.S. side. 
 
Finally, before turning out the lights in Anbar province in 2009, Kelly continued relationship-building with the tribes. When a Sunni leader died in U.S. custody, Kelly dispatched his own helicopter to return the fallen leader to his people. He directed the Sunnis to build a budget, then prodded the Shiite-heavy Baghdad government to fund it. America's senior combat leaders fashioned the victory in Iraq by mid-2008. 

Now that win has been squandered. The problem with the region remains. The chasm between Sunni and Shiite has widened, driving regional conflicts.

The Islamic State group Isis has incubated and thrived in the vacuum of U.S. leadership. The Russians, also, have entered the vacuum, partnering with Iran. Lots of nuclear reactors are being built in the region. And U.S. policy is in ruins.  
 
The next administration will need a savvy bunch of combat-experienced, senior officers with extensive relationships in the Middle East to rebuild. John Kelly and the rest of the "old hands" should be saddled up one more time. America needs them.