Gen. Martin Dempsey, the outgoing chairman of the Joint Chiefs of Staff, attends a hearing by the Senate Armed Services Committee. (Win McNamee/Getty Images)

Outgoing Joint Chiefs Chairman Martin Dempsey showed last week how much his understanding of the Middle East will be missed when he steps down.

In a blunt assessment given the Senate Armed Services Committee last Tuesday, Dempsey — who since 1991 has spent a good part of his career in the region — outlined the dilemma facing the Obama administration.

“While our potential adversaries grow stronger,” meaning the Islamic State and Iran, “many of our allies are becoming increasingly dependent on the United States and on our assistance,” meaning Iraq, Afghanistan, Yemen, Egypt, Lebanon, the Gulf States, Saudi Arabia, Jordan and Syrian moderates.

Dempsey’s nominated successor, Marine Gen. Joseph Dunford, has more limited experience in the Middle East. Dunford, who served in Afghanistan until last year, said during testimony before the same Senate panel on Friday that it had been years since he was in Iraq or dealt directly with the issues that are likely to consume President Obama’s foreign policy team before a new president is sworn in.

Dempsey described a convergence of trends in the Middle East that are complicating the United States having an effective role in the area.

“First,” he noted, “several governments are struggling for political legitimacy because they’re not sufficiently pluralistic or they’re not sufficiently accountable to their citizens,” he said.

Iraq would be the prime example, but that certainly applies to Afghanistan, Syria, Yemen, Bahrain and even to Saudi Arabia and Egypt, although Dempsey did not cite them by name.

“Second,” he said, “the centuries-old Sunni-Shia struggle is very evident.” That is certainly the case where the Sunni-dominated Islamic State is capitalizing on those long-standing frictions in Iraq, Syria, Yemen, Bahrain, Egypt, Libya and Saudi Arabia.

Finally, Dempsey said, “We’re seeing rising competition between moderate and radical elements of Islam, and ISIL [the Islamic State] and others are taking advantage of that competition,” particularly in Syria.

Overall, Dempsey expressed a skepticism about U.S. military intervention in the region. The emergence of the Islamic State and other problems in Middle East are “generational” issues that “military power alone . . . will not solve,” he said.

Beyond the broader differences in their backgrounds, the outgoing and incoming chairmen also may be at odds over the more narrow and immediate issue of embedding U.S. military personnel in Iraqi combat units.

Asked by Sen. Jeff Sessions (R-Ala.) whether Iraqi troops perform better with Americans embedded with them, Dempsey repeated his view that U.S. forward air controllers or advisers in tactical combat situations would not make a “strategic difference.”

“The silver bullet,” he said, “is getting Iraqis to fight.”

As he has before, Dempsey said that U.S. troops may need to accompany Iraqis in combat to go after major urban targets — such as Iraq’s second largest city, Mosul, which is now controlled by Islamic State fighters — “where there’s a major offensive where we think . . . its probability of success [could be increased] by our presence.”

Sessions got a somewhat different response from Dunford when he asked how the United States could encourage the Iraqis “to be more effective in fighting back” against the Islamic State.

Dunford, who commanded a Marine regiment in the 2003 invasion of Iraq and more recently ran assistance forces in Afghanistan, replied, “Clearly we need to do more to assist the Iraqis in moving forward and I — and I think that’s the plan.”

When Sessions asked whether embedding U.S. troops with Iraqi battalions made them “more effective on the battlefield,” Dunford said that his experience was that when U.S. forces accompanied Iraqi or Afghan troops, “those units are more effective.”

However, when Sessions pointed out that Dempsey had not recommended embedding a “small number” of American troops, Dunford responded that if he is confirmed, he would visit commanders in Iraq and provide a “recommendation to how we can move the campaign forward in Iraq.”

Dunford did not separate himself from Dempsey’s general approach, saying that in Iraq and Syria, the United States had to “build partnership capacity, if you will, of the local forces that would be the real defeat mechanism” for the Islamic State.

On Syria, however, Dunford did say something that other officials have obscured when asked why U.S. forces have not been used against Syrian government military targets.

Sen. John McCain (R-Ariz.) asked Dunford why Syrian recruits were required to sign a pledge that they would fight only against the Islamic State and not against the forces of Syrian President Bashar al-Assad. Dunford responded, “What I understand right now is that we do not have the authority to take action against Assad’s forces.”

He was referring to legal authority, lack of an administration request or an act of Congress on its own to authorize any military action beyond the 2001 law to go after those responsible for the attacks of Sept. 11, 2001, and the resolution in 2002 authorizing the invasion of Iraq.

Neither could be viewed as permitting the use of military force against the Assad government, and apparently in this case there is a need for some official authorization to go to war with another sovereign state — unless of course it attacks us first.