Plot hole: When Ryan and Clark are flying to Russia to look for those missing scientists, Clark shows Ryan some satellite pictures of the remote area where they suspect the scientists to be located. The day old photo shows activity in the area but the most recent one doesn't. They then discover that the bomb is headed for the U.S. and Ryan phones the CIA to warn them, But the bomb is already there! How did the bad guys manage to get the bomb from that remote location in Russia to a freighter and sail it to the U.S. in one DAY! This is something that should have taken weeks, which would have given Ryan plenty of time to get home and prevent the attack.
Plot hole: The Bedouin who found the unexploded nuke in the desert was supposedly dying of radiation poisoning when Clark questioned him. All he did was dig it out and load it in a truck, while all the shields were in place. If it was emitting THAT much radiation, the 3 scientists who spent DAYS refurbishing it for Dressler would have been made too sick by the radiation to finish the job.