IRAN crossed America's "red line" by killing its troops and Washington "must strike NOW" to prevent World War 3, a former US ambassador warned.
Mark Wallace told The Sun that Iranian terror chiefs should be preparing to be wiped out as the only "correct action" is a targeted blitz of their military bases inside Iran.
Wallace, former US ambassador to the UN, said: "President Biden established his red line with Iran, which was that if any US soldiers were killed, he would act decisively - that line has been crossed."
He stated that it's taken over 160 Iran-backed attacks on US assets for this moment to arrive but he hopes Biden "will honour the red line".
He said: "This is key to preventing World War 3.
"Without deterrence - war will break out with Iran.
"Iran has shown its behaviour in the past, they are a paper tiger, they press, press and press but when confronted - they will always withdraw.
"It is imperative that Biden honour his red line - and engage in decisive action now."
Wallace argued that the "correct action" must include the targeting the headquarters and bases of Iran's feared terrorist army, the Islamist Revolutionary Guard Corps (IRGC).
"From these sites, the IRGC has been able to enable and train its proxies to carry out barbaric attacks across the region in Israel, Iraq, Syria, the Red Sea," he said.
Today, US officials disclosed that Washington had finalised its plans for multi-day retaliatory strikes on Iranian personnel and targets inside Iraq and Syria, reports.
The planned strikes are a response to weeks of aggressive drone and missile attacks on US forces stationed across the Middle East amid Israel's ongoing war with Hamas.
The attacks reached a climax last Sunday as an Iran-backed militia launched a drone attack on a US base near the Jordan-Syria border, killing three troops and injuring dozens more.
Forces inside Iran must feel the wrath of the US
Mark Wallace
It was the first time American troops had been killed by enemy fire in the Middle East since the beginning of the war in Gaza.
Yesterday, Iran issuing a chilling warning that they are "not afraid of war" as tensions hit boiling point.
The head of IRGC, Maj Gen Hossein Salami raged: “We hear some threats from American officials about targeting Iran. We tell them that you tested us and we know each other.
"We do not leave any threat unanswered, and we do not look for war, but we are not afraid of it. This is the well-known truth.”
But former ambassador Wallace argued that General Salami "needs to find a mouse hole to hide in" if the US launches strategic strikes and targets Iranian leadership.
"Forces inside of Iran must feel the wrath of the US," he warned.
A former British general this week told The Sun that the US must inflict "severe violence" on Iran as quickly as possible or risk facing more attacks.
Colonel Richard Kemp said: ""It's not good enough just for the Americans to respond against Iranian proxies, now they must respond against Iran itself."
He explained that the US would have to launch a "significant" attack, not just a "tit for tat" response.
Kemp continued: "Iran needs to be taught a very strong lesson about America's deterrence.
"It needs to be a hit on IRGC positions, bases, and individuals resulting in severe destruction and death to Iranian terrorists who have been responsible for these attacks."
However, the US has not released what its current plans are - but targets have been chosen and plans finalised.
In a press conference this afternoon, US Secretary of Defence Lloyd Austin stated that this was a "very dangerous moment in the Middle East".
He said: "The president will not tolerate attacks on American troops and neither will I. Our teammates were killed by radical militants backed by Iran, operating in Syria and Iraq."
After Hamas's massacre on October 7, Iranian-backed rebels "have tried to create even more turmoil."
Austin added: "We will take all necessary actions to defend the United States, our interests and our people.
"We will respond when we choose, where we choose and how we choose."
In response to the deadly drone attack, Washington had vowed a "very consequential response" and warned that it would be coming soon.
US national security spokesman, John Kirby, said last night: "Just because you haven't seen anything in the last 48 hours, it doesn't mean that you're not going to see anything.
"The first thing you see won't be the last thing."
Iran denied involvement in Sunday's attack, however the Pentagon said it bore the "footprints" of Iran-backed Kataib Hezbollah in Iraq.
The Iraq-based terror proxy said it was standing down on Tuesday and announced the suspension of its military operations against US assets in the region.
The decision appeared to be triggered by fears over the expected US retaliatory strikes.
