Iranian terrorists take on the Great Satan on his own territory--in a competent, action-filled first thriller. It's the near future, and the Iranians, offstage since the entrance of Saddam Hnssein, muscle back onto the scene with a daring commando assault that sinks a US Navy amphibious assault ship in the Persian Gulf. The President, hoping to make his message rather clearer than his predecessors did, approves the complete destruction of the Iranian oil-pumping station on Kharg Island. The message just makes the Iranians madder. The mullahs order Major All Khurbasi, a commando whose hatred for America is deep and personal, to take a team of terrorists across the Atlantic, where they are to bomb the daylights out of the biggest Marine base on the East Coast and then scuttle up to Washington to assassinate the President in his own home. It's not impossible. Khurbasi has plenty of money, good inside information from an Iranian intelligence team in the US, and fanatically devoted soldiers. He also has the complacency of the Americans working for him. Fortunately for our side there is also Richard Welsh, a Marine veteran working for the Pentagon's Special Operations Command. Welsh, whose tactlessness keeps him on the outs with his superiors, saw the effects of Iranian fanaticism close up in Beirut, and he smells trouble when no one else smells a thing. Though beset by problems, the assault on the Marine base is horribly effective. The triumphant Iranians elude capture and speed on to their second objective. Mr. Welsh has to think very fast, indeed. Effective but, since blood flows by the bucketful, not for the squeamish. Unusually credible villains.