If Israel were to bomb Iran. Oil prices would immediately -- and gasoline prices could double. If -- -- then decides to attack oil tankers going through Google. According to ABC news analyst Richard... See More
If Israel were to bomb Iran. Oil prices would immediately -- and gasoline prices could double. If -- -- then decides to attack oil tankers going through Google. According to ABC news analyst Richard Clarke a former White House counterterrorism official. You could see very quickly Iranian commandos. And their small boats. Attacking tankers. Attacking oil platforms. You could see mines. Being laid in the gulf and if that starts to happen we're gonna see President Obama open up the strategic petroleum reserve. They would be a huge crisis in energy. It might not last long if the United States and its allies are able to retake control of the gulf but that could take more than a week. And under some scenarios it could take almost the moment. In the United States if Israel -- to -- -- American officials fear there could be a new wave of terrorism directed by Tehran. Especially if the US gets pulled -- to the conflict. If we the United States were bombing your rare. That I think that certainly would try to do something or our homeland. Because we -- her home. Already Israeli embassies and consulates and Jewish places of worship in the US have been put on alert. If Israel were to bomb Iran it would also likely set off the world's first international cyber war. With the US using capabilities. It has kept secret until now. The other states has is a very powerful ability. -- cause the sort of disruption to electric power grids communications networks. It hasn't done it because it doesn't like to expose its tricks. It's afraid that wants it does it people figure out. How the United States those. But in the war with a -- they would be willing to run that risk. But -- the US gets involved militarily Clark says it will be impossible to avoid American casualties the Iranians have. Hundreds. If not thousands of small boats armed small boats komando -- That will operate in the gulf. And they can give the and they can swarm. A US destroyer. The Iranians now also have cruise missiles anti ship cruise missiles so there is the potential. That the United States will as it did during the 1980s. During the year -- Iraq War. Will lose -- trip. Or two. And that there could be casualties to United States sailors operating ago. And if Israel bombs Iran Clark says the casket of events -- lead to attacks on Israeli cities by Iran. And the inevitable call to Washington. For help you'll very quickly received phone calls from prime minister Netanyahu to the president. And he will say to him only the United States Mr. President can find and destroy of these mobile missile launchers. Only you can save the lives of Israelis who were dying as -- speak in our cities. That message coming to any US president at any time is likely to cause us to go into action. But certainly coming to any American president who's running for reelection a few months later. It's likely to get a yes answer from the president and bring the US into the war. It is a worst case scenario gasoline prices double a wave of terror in American city. A scary world -- cyber war US military death. And American involvement in yet another war it did not want but a scenario Clark says that could unfold -- -- a week. If Israel decides to bomb suspected Iranian nuclear sites. Brian Ross ABC news New York.
This transcript has been automatically generated and may not be 100% accurate.