If the medium is the message, as the Canadian scholar Marshall McLuhan put it, the Iranians couldn't possibly mistake the recent communications by the United States.

On Tuesday, President Bush told reporters that the Israeli bombing of an alleged North Korean-designed nuclear facility in Syria was not just directed against Pyongyang and Damascus, but was also a not-so-subtle telegram to Tehran.

Answering a question about the sudden resurfacing of the Sept. 16 attack on the Syrian facility, Bush strongly suggested that the United States and Israel had Iran in mind when Syria was bombed:

We have an interest in sending a message to, to Iran, and the world, for that matter, about just how destabilizing a nuclear proliferation would be in the Middle East, and that it's essential that we work together to enforce U.N. Security Council resolutions aimed at getting Iran to stop their enrichment programs. In other words, one of the things that this example shows is that, you know, these programs can exist and people don't know about them and - as the Syrians simply didn't declare the program. They had a hidden program.

Syria has denied that the site was a nuclear reactor. Arms experts say a country doesn't have to declare a nuclear reactor unless it is about to fire it up. Iran insists its sprawling and expanding network of nuclear facilities are meant for peaceful purposes only. It has opened them to international inspectors.

Meanwhile, in another possible message to Iran, the United States dispatched a second aircraft carrier group to the Persian Gulf.

It's not that big of a deal. The number of U.S. warships in the Gulf supporting the missions in Iraq and Afghanistan typically fluctuates. Defense Secretary Robert Gates downplayed the significance of the move. He told reporters in Mexico that the United States was not laying the groundwork for a strike against Tehran, which he has accused of supplying weapons and training to militants fighting U.S. soldiers in Iraq.

But he added that the warships could be seen as a "reminder" to Iran, presumably of America's ability to bomb the country.

U.S. officials hope they can cajole Iran into halting alleged support for Iraqi militants and curtailing its nuclear program by waving the big stick of military intervention.

But some Iran experts say the strategy won't work and might even have the opposite effect, emboldening the government of President Mahmoud Ahmadinejad.

Here's a note from Karim Sadjadpour, an analyst at the Carnegie Endowment for International Peace:

The Bush administration thinks that invoking the military option scares the Iranians. I think it is music for Ahmadinejad's ears. Bombing Iran is the one thing that would really rehabilitate his presidency and perhaps even improve the Iranian economy as oil prices would skyrocket. In the last seven years I don't recall any examples of Iranian behavior improving as a result of U.S. military threats or name calling. It may feel good, but it doesn't work.