(CNN) President Donald Trump's targeted killing of Iran's ruthless military and intelligence chief adds up to his most dangerous gamble yet with other peoples' lives and his own political fate.

By killing Qasem Soleimani in Iraq, Trump committed the United States to a risky open conflict that at best could stop short of all-out war with Iran that could cause national security and economic shocks in the United States and across the globe.

The administration argues that it has taken one of the world's worst mass murderers and terrorists off the battlefield. But given Iran's easy access to soft targets, the Middle East and even Europe suddenly look a lot less safe for Americans , including US troops Trump may be even more tempted to haul home.

Two days into his re-election year, Trump -- who rails against Middle Eastern entanglements -- has plunged the United States into another one, with vast and unknown consequences. It challenges a presidency that is already alienating half of his country, following his impeachment and unrestrained behavior in office. Trump may find it impossible to rally the nation behind him to weather the crisis. He has also scrambled strategic and moral expectations of the United States -- ordering the killing of a senior foreign leader of a nation with whom the US is not formally at war -- albeit an official regarded by Washington as a terrorist.

Reflecting the strike's potential for escalation, a US defense official said the administration would deploy a further 3,000 troops to the Middle East, including 750 who have already deployed to protect the US embassy in Baghdad.

The reverberations of his act on Thursday will last for years.

"Iran never won a war, but never lost a negotiation!" Trump wrote on Friday morning in a tweet that will do nothing to calm critics who worry about the depth of his strategic thinking.

It is too early to know whether Soleimani's death will significantly weaken Iran and improve the US strategic position, whether it will ignite a regional conflagration and how it will eventually affect Trump's political prospects and legacy. It is also unclear how it will change the political position inside Iran where the regime is besieged by an economic crisis and recently crushed mass protests.

But Iran will surely regard the killing of one of its most significant political leaders as an act of war, so its revenge is likely to be serious and long lasting.

"There are definitely going to be unintended consequences, and for starters I think we better have our embassies pretty well buttoned down," former US Ambassador to Iraq Christopher Hill told CNN.

"Iran simply cannot sit on its hands on this one. I think there will be a reaction and I'm afraid it could get bloody in places."

Trump supporters are celebrating their hard man commander-in-chief. They note that Soleimani orchestrated the deaths of hundreds of US soldiers in militia attacks during the Iraq War. But recent history is marked by spectacular US shock-and-awe opening acts of conflicts in Iraq and Afghanistan that cause short-term gloating and long term military and political disasters. A full-on conflict with Iran would be far more complicated than those two wars.

Trump's strike may be the most significant calculated US act in a 40-year Cold War with revolutionary Iran. It's the biggest US foreign policy bet since the invasion of Iraq.

Secretary of State Mike Pompeo told CNN's "New Day" that killing Soleimani "saved American lives" and was based on "imminent" threat intelligence about an attack in the region. Trump echoed his secretary of state later Friday morning, tweeting that Soleimani "was plotting to kill many more" Americans.

But Pompeo refused to give further details. The political bar for an administration that has made a habit of disinformation and lying is going to be far higher than that in such a grave crisis. Eliminating the most powerful political force in Iran short of Supreme Leader Ayotollah Ali Khamenei also destroys the chimera that this White House is not committed to a regime change strategy.

Given Soleimani's frequent travels to Iraq, Syria and other areas in the Middle East this is not the first time that he will have been in US crosshairs. But previous presidents, perhaps cognizant of the inflammatory consequences, chose not to take the shot. In the coming days, the administration will have to explain why it acted now.

The act also likely eliminates possibly for a generation, any hope that the United States and Iran can settle their differences by talking. There will be no desire nor political capital for even Iranian officials often misleadingly described as moderates to sit down with US counterparts.

Trump owns the aftermath

When Trump took office, there was no immediate crisis with Iran. The Islamic Republic was honoring the Obama administration's nuclear deal though it had not stepped back from its missile development and what the US says is malignant activity in its own neighborhood.

But by ripping up the deal, strangling the Iranian economy and now killing Soleimani, Trump now owns however the confrontation turns out. It's a huge gamble because history suggests that Presidents who bet their careers on the jungle of Middle East politics always lose.

The strike displays Trump's growing infatuation with wielding military power, exacerbates a trend of unchecked presidential authority and forges the kind of ruthless vigilante image he adores.

The question is now whether Trump -- an erratic, inexperienced leader who abhors advice and rarely thinks more than one step ahead -- is equipped to handle such a perilous, enduring crisis.

And is his administration, which seems bent on toppling Iran's regime but cannot publicly come up with a plan for the aftermath, ready to handle an Iranian backlash in the region and beyond?

Trump's hubristic tweeting of a US flag following Soleimani's death in a drone strike in Iraq but failure to explain to Americans what is going on may be a bad sign in this regard.

But despite a stream of instant Twitter analysis from pundits suddenly expert in Iranian affairs, no one can be sure what will happen next. That's what makes Trump's strike so unpredictable and potentially dicey.

With the vast network of proxies from Hezbollah to Hamas, Iran has the capacity to strike fast and hard against US allies like Israel and Saudi Arabia and US assets and personnel in its region. It could hammer the global economy by attacking oil tankers in the Strait of Hormuz. US officials and top military officers may be more exposed when they travel abroad. Iran could explode Lebanon's fragile political compact and causes region-wide shocks.

US troops in Iraq, Syria and Afghanistan look especially vulnerable to action by Iranian-allied forces. Politically, the Baghdad government may have no choice but to ask American forces to leave after the attack in a scenario that could effectively deliver the country to Iran's influence or retrigger its terrible civil war.

The killing of Soleimani is a massive symbolic blow to Iran. He was the Godfather of the Middle East who masterminded the country's huge regional influence.

Pompeo claimed that his demise will be greeted by Iraqis and Iranians as a blow for freedom and a sign the United States is on their side. But developments in Middle Eastern politics rarely mirror the optimistic pronouncements of US officials.

Did the US inflict a serious strategic blow on Iran?

Analysts will be looking to see whether the death of Soleimani robs the Quds force of the Iranian Revolutionary Guards Corps of its coherence and dims its regional power at least at first.

Tehran's strategic response is unclear. While it could lash out, a wave of attacks against US soldiers or terrorist strikes elsewhere may draw it into a direct conflict with a more powerful rival, the United States that it does not seek.

It is not certain that it will strike back quickly. It may have more to gain from making life intolerable for the United States and its citizens in the region in a slow burn approach.

Trump could be especially exposed to a such a military or economic backlash by Iran that casts doubt on his judgment given his quickening reelection race.

His move against Iran could also reshape the dynamics of the presidential election race at home, by opening a lane for Democrats to run as anti-war candidates against him -- a position that helped the last two presidents -- Trump and Barack Obama -- get elected.

Democratic candidate Bernie Sanders on Friday released a video vowing to do everything he can "to prevent a war with Iran."

"Because if you think the war in Iraq was a disaster, my guess is that the war in Iran would be even worse," the Vermont senator said.

And Democratic front-runner Joe Biden immediately swung into sober commander-in-chief mode, positioning himself to profit politically if Trump's Iran venture backfires.

The former vice president offered testimony to Soleimani's record of fomenting bloodshed and instability but added: "President Trump just tossed a stick of dynamite into a tinderbox."

"He owes the American people an explanation of the strategy and plan to keep safe our troops and embassy personnel, our people and our interests, both here at home and abroad, and our partners throughout the region and beyond," he added.