The United States’ killing of Maj. Gen. Qasem Soleimani, Iran's most influential military commander, left his country in shock; this wasn’t an expected scenario in the middle of a crisis that was thought to be under control between Tehran and Washington in the aftermath of the latter’s withdrawal from the nuclear deal in May 2018.

Nor was this part of the pattern Iranian officials had grown used to during an escalation that started in May with several unclaimed incidents in the Persian Gulf, the June downing of an advanced US drone near the strait of Hormuz by Iranian fire and the September attack on Saudi Arabia’s biggest oil refinery claimed by the Yemeni Houthi group.

While the United States blamed Iran for all three sets of events, Washington had not reacted militarily, but rather had vowed more sanctions and stressed that it was not seeking a war in the region.

Then the Iranians were caught by surprise twice. First was when US forces retaliated for the attack on the K1 air base in Kirkuk that killed an American contractor by killing 25 members of Iran-backed Popular Mobilization Units (PMU) in one strike. The second was when the US strike ended the life of the Islamic Revolutionary Guard Corps commander Tehran regards as its revolutionary icon, known as Haj Qasem, following the siege of part of the US Embassy grounds in Baghdad. It seems obvious that the United States is now employing a tit-for-tat strategy.