For at least a year, the U.S. has tried to keep Israel from attacking Iran, usually by arguing that sanctions on Tehran are working and that American can hit harder if it comes to a fight. It's a delicate balance, especially since President Obama and Prime Minister Benjamin Netanhayu trust each other only slightly more than they trust Iranian President Mahmoud Ahmadinejad. Now Iran might have upset the balance – even though Iran has an entire arsenal of U.S. guns floating just off its shores.

On Wednesday, a terrorist attack killed at least seven Israeli civilians vacationing in Bulgaria. Netanyahu immediately blamed Iran, and promised a "strong response against Iranian terror."

Maybe Iran pulled the trigger. Maybe it didn't. Netanyahu's defense minister, Ehud Barak, was far less categorical. He said the attack was saying "initiated probably by Hezbollah, Hamas, Islamic Jihad or another group under the terror auspices of either Iran or other radical Islamic groups." Regardless, he promised to "settle the account" with whoever was responsible for the strike.

If Iran actually was behind the attack, it did so in spite of having a massive amount of U.S. naval power aimed at it. The U.S. has quietly but persistently built up a massive naval presence around Iran that outclasses most of the world's navies. It's about to launch a huge exercise with over 20 nations that will demonstrate how to defeat an anticipated Iranian tactic. And this doesn't even get into anything the U.S. does with Israel.

Even before word of the Bulgaria attack reached the Pentagon, Defense Secretary Leon Panetta gave Iran his best come-at-me-bro. Should Iran decide to close the Strait of Hormuz, a chokepoint for global oil shipping, he said, "We've invested in capabilities to ensure that the Iranian attempt to close down shipping in the Gulf is something that we are going to be able to defeat."

And how. On Monday, the Navy and U.S. Central Command announced that they're going to call the aircraft carrier USS John C. Stennis back to the Mideast four months ahead of schedule, so the Navy can maintain two aircraft carrier strike groups near Iran for the foreseeable future. No other nation on earth has two full-sized aircraft carriers; the Navy is parking two of them near Iran as an unsubtle threat.

It's not just the carriers. Over the past several months, the Navy has sent a lot of hardware to the Persian Gulf. Extra patrol craft retrofitted with Gatling guns and missiles. Littoral Combat Ships. Minesweepers. MH-53 Sea Stallion helicopters. Advanced torpedos. A new kind of underwater drone. A new kind of floating base. A new special-operations task force.

Beyond that, two months from now, 20 nations will come together for a ten-day naval drill practicing how to defeat mines placed in Mideast waterways. The Pentagon swears that the exercise has nothing to do with Iran, but that's nonsense. Mining the Strait of Hormuz is a recent theme of Iranian rhetoric, and nothing will spur nearly two dozen countries into concerted action faster than the disruption of 20 percent of the world's oil. For ten days in September, Iran will watch lots of militaries practice how to defeat it.

On the other hand, Iran might have good reasons for thinking an attack on Israel made sense. Its nuclear scientists – who are civilians, remember – keep getting killed. The Stuxnet worm targeting its nuclear infrastructure was all-but-officially outed as U.S.-Israeli collaboration, as was the complex piece of spyware known as Flame. Elements within the regime might think the U.S. doesn't respond forcefully to Iranian provocations.

All of these things can be true. Nations miscalculate their interests all the time. But none of that changes the objective fact that the stronger party is floating off the coast of Iran, and it's building strength in the region by the day.