The news came out Monday that Iranian fast-attack craft had once again harassed US Navy ships in the Persian Gulf with unsafe and unprofessional behavior, forcing the USS Mahan to fire warning shots.

The incident, the first of its type reported this year, follows a significant increase in Iran’s navy harassing US ships in 2016, the US Navy has told Business Insider.

Iran’s ability to undermine the West, to harass their ships in international waters, and to look militarily strong while having weak conventional forces owes to Tehran’ ;expert handling of the US diplomatically and militarily, according to Behnam Ben Taleblu, a senior Iran analyst at the Foundation for Defense of Democracies.

Although the US lists Iran as the No. 1 state sponsor of terror and has accordingly moved to sanction Iran over the past few decades, the actions have not been enough to deter Iran. According to Taleblu, “sanctions are an important step, but they’re not the only step.”

In addition to sanctions, the US would benefit from a signaling its resolve against Iran, where the Obama administration has been seen as “phobic” in confronting them.

Read the whole story from Business Insider.

Featured image courtesy of Reuters.