Iran is playing the rodeo clown. If you've been to a rodeo, you've no doubt seen the clown distract the angry bull away from the downed rider.
Well, the "downed rider" in the Middle East is Hezbollah (because Syria recently withdrew its Army from Lebanon that was protecting Hezbollah from a U.S./Beirut/Israeli ground war).
Right now Iran is bluffing; saying anything provocative. The effect is to tell the bull to "look at me over here!" instead of looking at Hezbollah.
And Hezbollah is in a world of trouble because the last prisoner exchange with Germany (German hostage held in Iraq for a PFLP terrorist in Germany) exposed the extent of involvement of Hezbollah in Iraq...and under President Bush, that's a very bad thing for Hezbollah...because GWB isn't afraid to use our military to end such shenanigans.
Also keep in mind that Hezbollah is funded by Iran to be Iran's proxy. Hezbollah in near-autonomous Southern Lebanon can do things that would otherwise start an open shooting war if Iran directly did it instead.
And Iran does not want to lose Hezbollah...hence, the Persian Rodeo Clown dance is now on the radio.