Rodman RIPS Obama Over North Korea -- 'He Can't Do S**t'

Dennis Rodman tells TMZ ... he's going back to North Korea on August 1 to reopen the political dialogue with Kim Jong-un ... because Barack Obama "can't do s**t."

Rodman was out in L.A. yesterday when we asked about his plan to head back to DPRK to visit his tiny, little, missile-obsessed "friend" with the weird haircut.

The Worm told us he'll do everything in his power to sway Jong-un into releasing American Kenneth Bae -- who was sentenced to 15 years hard labor in North Korea for allegedly plotting to overthrow the government.

"I'm gonna try and get the guy out," Rodman said ... "It's gonna be difficult."

Then came the Obama attack -- "We got a black president [who] can't even go talk to [Jong-un] ... Obama can't do s**t, I don't know why he won't go talk to him."

A short time later, Rodman continued the anti-Obama talk -- saying, "Obama? F**k him!"

Despite all the political talk, Rodman insists, "I'm not a diplomat."

Sure pal ... just get the guy out and we'll talk.