If the Obama administration believes that the Islamic Republic of Iran can eventually be compelled to evolve into a responsible regional actor and a force for stability in the Middle East, they have a lot of work ahead of them.

In April, Iran sparked an international incident when Islamic Republic patrol boats fired on and boarded the Marshall Islands-flagged cargo ship Maersk Tigris in the Persian Gulf. The boat was then directed into an Iranian port and detained for several days.

This was not the first time that Iranian naval forces acted as a menace in that critical international shipping lane. Shortly after that episode, American officials revealed that Iran had attempted to intimidate an American-flagged ship in a similar manner just days earlier.

Unfortunately for America’s Marshall Islands ally, a nation which the United States is bound by treaty to protect, Pentagon lawyers determined that the Maersk ship had briefly strayed into Iranian waters and the U.S. had no obligation to come to the defense of that nation’s ship while at sea.

On Thursday, CNN reported that Iran has again engaged in provocative and destabilizing behavior in the Gulf. According to reports, five Iranian gunboats approached a Singapore-flagged cargo vessel in the Persian Gulf and fired warning shots across its bow.

That vessel reportedly than engaged in emergency maneuvers, turned away from an international shipping lane, and escaped into the territorial waters of the United Arab Emirates. “At that point, there’s a lot of drama here, the UAE sent three of its cargo vessels out to protect the ship that was now in its national waters, and the Iranian’s turned back,” CNN security reporter Barbara Starr reported.

The strength of American hegemony is best measured by the freedom with which commercial vessels navigate international shipping lanes unimpeded. As the nation best equipped to project power abroad and which enjoys near monopoly control over the waves, only the United States can guarantee global free transit. To attack a trade ship is a direct threat to American interests and the geopolitical order.

What’s more, the feeble American response to an Iranian attack on a nation’s vessel that Washington is treaty-bound to protect almost guaranteed that Iran would again engage in this kind of provocation. Eventually, those nations involved in global trade will no longer leave their security up to chance when transiting through the Persian Gulf. Eventually, the world will no longer rely on a lethargic United States to provide protection and will ensure their trade vessels have an armed accompaniment.

This will dramatically increase the region’s volatility, and all in service to the president’s myopic and self-serving need to secure a legacy achievement in the form of a nuclear deal with Iran. How terribly irresponsible.