The United States and Iran have been arch-enemies for decades, and a full-scale war is never far away.  

Recently, the relationship has been very tense, partly because the US left the international nuclear energy agreement and imposed harsh sanctions on Iran, partly because the US in January 2020 killed the Iranian top general Qassem Soleimani in a drone attack in Baghdad. 

After the targeted assassination, Iran vowed revenge and several times in the past year, Iranian-backed militias have attacked US targets in Iraq.

And they have also sworn that more retaliation will come.

Want to send a clear signal

On February 15 this year, rockets were fired at a US-Kurdish military base in Erbil, Iraq.

One person was killed and six were injured.

The attack can be seen as a test against the new US President Joe Biden to see what the Iran-backed militias can get away with. 

Tonight, the United States and Biden's response came. 

After taking a closer look at several options, the United States chose to air bomb Iran-backed militias in Syria.

The target was premises on the border between Syria and Iraq used by several militias to smuggle weapons and soldiers. 

The new administration in the White House wants to punish Iran for the rocket attack in Erbil and at the same time send a clear signal that the United States does not allow Iran to use proxy militias in Iraq, Syria or any other country in the region.  

That US retaliation was relatively limited and took place in Syria is probably due to President Joe Biden not wanting the military confrontation to escalate.

Biden has plans to resume talks with Iran on a new nuclear energy agreement. 

The spiral of violence continues

But from the point of view of Iran and the militias, it is of course different.  

The US airstrike on Friday night killed at least 17 militiamen.

Voices are now being heard again calling for revenge, both from hardline politicians in Tehran and from various militias that Iran does not always control.  

The spiral of violence in the Middle East is just continuing. 

The US air strike on Iranian targets in Syria is Joe Biden's first known military action as president.

But certainly not the last.