For the second day in a row, US warships and Iranian patrol  boats tangled in the Persian Gulf with the incident on Wednesday resulting in warning shots fired at the Iranian vessel.

On Tuesday, 4 Iranian Revolutionary Guard Corps craft buzzed around several US patrol vessels, conducting what was described as a "high speed intercept" of at least one American warship. The IRGC patrol boats came within 300 yards and were warned numerous times before moving away.

The confrontation on Wednesday was between the USS Nitze and a lone IRGC patrol boat.

Reuters:

A U.S. Navy ship fired warning shots toward an Iranian fast-attack craft that approached two U.S. ships, a Pentagon spokesman said on Thursday, in the most serious of a number of incidents in the Gulf area this week.

"They did feel compelled ultimately to fire three warning shots and the reason for that is... they had taken steps already to try and de-escalate this situation," spokesman Peter Cook told reporters.

Tensions have increased in the Gulf in recent days despite an improvement in relations between Iran and the United States.

Years of mutual animosity eased when Washington lifted sanctions on Tehran in January after a deal to curb Iran's nuclear ambitions but serious differences still remain over Iran's ballistic missile program, Syria and Iraq.

Improvement? What planet are these people from? Since the signing of the nuclear deal, Iran has seized more American hostages, flown drones over our fleet in the Gulf, seized our sailors, fired a missile in the vicinity of our ships, and harassed a ship carrying CIC Central Command. The doesn't include the constant "Death to America" chants that continue to echo from every mosque in the country.

Some "improvement," huh.

A U.S. defense official, speaking on the condition of anonymity, said the USS Squall patrol craft fired three warning shots from a .50 caliber gun in the northern Gulf on Wednesday after warning flares did not work.

The incident started with three Iranian vessels, but there was only one around by the time the warning shots were fired, the official said. He described the Iranian behavior as "unsafe, unprofessional, and not routine."

At one point, the Iranian vessel came within 200 yards (193 meters) of a U.S. ship, the official said.

Another interaction took place between an Iranian and U.S. ship on Wednesday, the defense official said but gave few more details.

This constant testing is Iran's way of waging war. They want the propaganda benefits of victory without actually fighting. As long as President Obama is in office, the US will not engage militarily given the probability that any such incident would lead to the scuttling of the nuclear deal.

Iran knows this full well and is taking ruthless advantage of our weakness. Their bellicose actions in confronting US vessels in international waters are illegal and dangerous. But the US - and the international community - won't lift a finger to stop them.