There's blood on the streets of Tehran, but only bloodless platitudes coming from the White House.

Despite his fast support for protesters in Egypt, President Obama seemed bored yesterday with reports of protesters trying to end the thugocracy in Iran. Twice in his press conference, reporters gave him a chance to express enthusiasm for the dissidents, and twice he swung half-heartedly at the pitch.

What he did say had the ring of formality and falsity. "We were clear then and we are clear now," he said about his support for Iranian demonstrators in 2009.

In truth, he was too deferential to the regime then, and he strangely remains so now, even though it is beating and executing its critics.

"These are sovereign countries," he said, adding that the most America can do is "lend moral support."

He did not limit himself when Egypt was on fire, demanding that our ally, Hosni Mubarak, begin a transition of power "now."

He clearly signaled that the United States wanted change and would not support a crackdown, and the president said yesterday that history would show we were on the right side.

Given the odds against an uprising in Iran, perhaps Obama's tepid endorsement reflects that "pragmatist" streak his supporters chirp about. But to pass on an opportunity to support Iranian demonstrators directly is to make pragmatism look obscenely weak.

With the mad mullahs marching toward the bomb and sponsoring terror throughout the Mideast, including against our troops in Iraq, Iran is the world's No. 1 menace.

Regime change in Egypt could turn out badly for American interests if Islamic extremists take power, but any change in Iran would almost certainly be for the better.

Read Michael Goodwin's Complete Column at NYPost.com