Former defense secretary Donald Rumsfeld, who played a major role in the United States going to war in Iraq and Afghanistan last decade, says President Obama hasn't made his case for military intervention in Syria.

"One thing that's very interesting, it seems to me, is that there really hasn't been any indication from the administration as to what our national interest is with respect to this particular situation," Rumsfeld said on Fox Business Network on Wednesday.

Rumsfeld said the two most important things in the region are Iran's nuclear capabilities and the relationship between Iran and Syria with respect to funding terrorism.

He suggested getting involved militarily wouldn't help on either issue.

Rumseld also echoed GOP criticisms of the leaks from the Obama administration about what it might do and when, in response to the Assad regime's alleged use of chemical weapons against civilians.

"The idea of demystifying what you're going to do for the enemy is mindless," Rumsfeld said. "I can't imagine what they're thinking, why they would want the Assad regime to have crystal clarity...."

Rumsfeld said Secretary of State John Kerry has been "dealt a pretty bad hand," thanks to Obama and the previous secretary, Hillary Clinton.