Fortifying security around the US embassy and bases in Iraq has begun but experts fear the US and Iran could be entering a spiral of escalation that could complicate American presence in the country. US President Donald Trump blamed Iran for Tuesday’s embassy attack and called Iraqi Prime Minister Adel Abdul Mahdi to stress “the need to protect United States personnel and facilities in Iraq". Mr Trump’s confidant, Lindsey Graham, a US senator who is with him in Mar-a-Lago, said Iran needed to tread carefully. "To the Iranian government: be careful what you wish for," Mr Graham said on Twitter. "A country that depends on the ability to refine oil for its existence needs to be cautious. "President Trump, unlike president Obama, will hold you accountable for threats against Americans and hit you where it hurts the most. Choose your battles wisely." Experts told <em>The National </em>that there were limited options for the US and urged restraint. These were their responses: The situation is very challenging for the Trump administration because it has staked its credibility in Iraq on the basis that it can push back Iran in Baghdad. This is politically controversial at best for many Iraqis. What is unfolding now in Iraq is that Iran-backed groups such as Kataib Hezbollah have the capability to respond to American escalation through non-kinetic means, such as targeting the US embassy with mass protests, which are challenging for the US to respond effectively against. The Trump administration should now demonstrate restraint and work through Iraqi authorities in the future to constrain the Iran-backed, Iraqi groups. The United States was arrogant in its initial response [strikes on Kataib Hezbollah] on Monday. The US violated Iraqi sovereignty in exactly the same way as Iran does. Those fighters may have deserved that response, but it was so brazen and without thought. It created an escalatory pattern that has upended Operation Inherent Resolve and now risks the US presence in Iraq. Further, the escalatory ladder creates the variables for the next strike to be in Iran proper, something that would be even more provocative and would entail an Iranian response. This is all very surreal because the Trump administration is arrogant enough to think they can control this. The primary response will signal that the US embassy in Baghdad is secure. The dispatching of about 100 marines to Baghdad is part of that, as are the flyovers over the capital. This response will be restrained in an attempt to not give pro-Iranian factions in Iraq more ammunition to argue that the US should be ejected from the country. So far, it's important to note that the storming, while alarming, didn't cross any major US red lines. They didn't get in too deep inside the embassy and no one was killed. It is a symbolic retaliation designed to exacerbate the tensions between Baghdad and Washington. The Trump administration’s maximum pressure strategy on Iran implies zero incentives for de-escalation on either side. The US can hurt Iran but cannot compel it to concede. Iran can impose higher cost on the US for its strategy but is in no position to force a change. Now the two are stuck in an escalation spiral.