"Bombs away" should not be the first military response from the United States, but respond we must. Closing international waters is a blockade – essentially an act of war against other states.

Were we to stand idly by and let any nation shut down a vital international passage, it would lend credence to the view that the United States is now too weakened and timid to defend its sovereign rights. To ignore such aggression would be like giving the Barbary Pirates a pass when they ravaged U.S. shipping in the early 1800s.

And, don't buy the line that it's none of our business. Over a third of the world's oil transported by sea goes through the strait. If that flow stops, you can bet the farm it will cause huge problem here at home.

When the Heritage Foundation war-gamed this scenario back in 2007, the impact was immediate: a near doubling in the cost of a barrel of oil and a loss of 1 million domestic jobs.

Though closing the straits is an act of war, responses in war ought to be proportional. Thus, the first U.S. military objective ought to be to reopen the straits, and you don't have to attack Iran to do that.

Consider 1987, when Iran tried to interfere with the passage of oil through the strait. President Ronald Reagan authorized Operation Ernest Will. The U.S. Navy protected ships going through the straits and only conducted military operations in defense of the tankers or U.S. forces.

That should be the going-in strategy today. If Iranian attacks were to persist, then a proportional and responsible act would be to take out the bases or support infrastructure where the attacks originate.

And if the Iranians still didn't get the message, the target set should then be expanded to things that the regime values: targets like the Iranian Revolutionary Guard Headquarters, government facilities, and other military facilities – including those contributing to Tehran's nuclear weapon and ballistic missile program.

Going after these targets might require taking out Iranian command and control and air defense sites. That would be justified.

At no point along the way would the United States need to ask the United Nations or anyone else for permission. The United States would just be exercising its inherent right as a nation to act in self-defense.

It is worth noting that we wouldn't find ourselves seriously contemplating such high-seas drama and tragedy today if the White House had spent the last three years working to put an aggressive Iran back in its box. Iranian hostility toward the United States was no secret when President Obama took office.

Tehran had been a declared state-sponsor of terrorism since the 1980s. It's illegal nuclear weapons program had long been an open secret. So, too, was the regime's institutional support in killing U.S. soldiers in Iraq.

Yet this administration wasted most its first three years trying to "engage" this rogue regime. Little wonder Iran treats the U.S. with contempt and threatens reprehensible acts against international commerce even as it continues to prop another of the world's worst dictators in Syria.

Playing nice with Tehran, coupled with the premature withdrawal of stabilizing U.S. troops from Iraq, have brought us to where we are today. If the United States has to draw swords to protect our interests in that part of the world, it will be because this White House failed us.

Odds are Tehran won't try to close the strait. It knows the United States would have to reopen the passage. But the mullahs also know that the last thing Obama wants is another war before the election.

So as long as they pull up short of actually interfering with shipping, the Iranians feel they have a free pass to bluster and taunt the U.S. with impunity.

James Carafano is the director of the Allison Center for Foreign Policy Studies at The Heritage Foundation.