Los Angeles Times | Tracy Wilkinson, Melissa Etehad, Chris Megerian: In ordering the killing of Gen. Qassem Suleimani, one of Iran�s highest-ranking officials, President Trump has taken one of the biggest gambles of his presidency � a step that appears to lead the U.S. on a path toward escalated warfare and that marks a sharp break from his often-stated desire to pull American forces out of conflicts in the Middle East.

Throughout his presidency, Trump has made fiery statements, but has typically resisted dramatic belligerent actions. He has promised his supporters that he would use decisive violence against U.S. enemies, but he also promised to stay out of wars in the Middle East and to bring U.S. troops home.

Outside analysts � and some of Trump�s former advisors � have repeatedly warned that those two pledges could not be reconciled.

Until now, when his goals clashed, Trump has typically pulled back. In June, for example, he gave a last-minute order to stop an airstrike against Iran planned in retaliation for Tehran�s shooting down of an unmanned American drone. Nor did he order a military response to attacks on Saudi oil installations in the fall that U.S. and Saudi officials blamed on Iran.

The decision to kill Suleimani, the head of the Islamic Revolutionary Guard Corps� elite Quds Force, who was sometimes described as the second-most powerful official in Iran, marks a radical shift. It appears to represent a bet that Iran, faced by a decisive U.S. military action, will back down, not escalate.

Iran will now have to �reexamine the limitations of the violence they can bring to the table,� said one senior congressional Republican official, speaking on condition of anonymity. The official predicted �some face-saving retaliation in Yemen or Lebanon, maybe Afghanistan,� but not more.

Others were deeply skeptical of such assertions. While the U.S. undoubtedly has overwhelming superiority in conventional military power, the Iranians, even without Suleimani, will be able to launch guerrilla-style operations throughout the Middle East and possibly beyond, they said.

Iran�s supreme leader, Ayatollah Ali Khamenei, said in a statement that �a harsh retaliation is waiting.�

�The U.S. and Iran have been engaged in a dangerous tit-for-tat for months now, but this is a massive walk up the escalation ladder,� said Charles Lister, a senior fellow at the Middle East Institute in Washington. �There really is no underestimating the geopolitical ramifications of this.�

While U.S. forces have killed leaders of Al Qaeda and other militant groups, targeting high-ranking officials of other governments has been a line that American officials have seldom crossed except during wars.

Not since President Reagan ordered an airstrike against Libya in 1986 that came close to killing that country�s leader at the time, Moammar Kadafi, has the U.S. taken an action comparable to the attack on Suleimani.

To heighten the political risk, Trump appears to have acted without advance consultation with Congress, breaking with long-standing practice. Congressional Democrats quickly criticized the president for acting unilaterally.

�The Administration has conducted tonight�s strikes in Iraq targeting high-level Iranian military officials and killing Iranian Quds Force Commander Qasem Soleimani without an Authorization for Use of Military Force against Iran. Further, this action was taken without the consultation of the Congress,� House Speaker Nancy Pelosi (D-San Francisco) said in a statement.

�The full Congress must be immediately briefed on this serious situation and on the next steps under consideration by the Administration,� she said. �We cannot put the lives of American service members, diplomats and others further at risk by engaging in provocative and disproportionate actions. Tonight�s airstrike risks provoking further dangerous escalation of violence.�

Administration officials say that Trump authorized the strike because Suleimani, who has long directed the actions of Iranian-backed militia groups that have attacked U.S. forces in Iraq and elsewhere, was planning further attacks on American personnel.

�Gen. Suleimani was actively developing plans to attack American diplomats and service members in Iraq and throughout the region,� Defense Secretary Mark Esper said in a statement. �This strike was aimed at deterring future Iranian attack plans.�

Critics, however, accused Trump of recklessness.

�President Trump just tossed a stick of dynamite into a tinderbox,� former Vice President Joe Biden said in a statement.

�He owes the American people an explanation of the strategy,� added Biden, a leading Democratic presidential candidate.

�No American will mourn Qassem Soleimani�s passing. He deserved to be brought to justice for his crimes against American troops and thousands of innocents throughout the region. He supported terror and sowed chaos,� Biden said.

But, he added, �this is a hugely escalatory move in an already dangerous region.�

The immediate chain of events leading to the strike began late in December when a missile attack against an Iraqi military base killed an American contractor. U.S. officials blamed the attack on Iranian-backed militia groups and responded with airstrikes that killed 25 people.

That in turn led to the storming this week of the U.S. Embassy compound in Baghdad by pro-Iranian militia members. At that point, a senior administration official said Thursday, the �game has changed.�

Administration supporters said the strike would be a major setback to Iran.

Suleimani�s �death is a huge loss for Iran�s regime and its Iraqi proxies, and a major operational and psychological victory for the United States,� said James Carafano of the conservative Heritage Foundation, which often advises Trump on foreign policy.

Ariane Tabatabai, a Middle East expert at Rand Corp., said the killing of Suleimani sent a strong symbolic message to Iran and its allies, though it won�t lead to the collapse of the Islamic Revolutionary Guard Corps or Iran�s network of non-state allies. From Afghanistan to Lebanon and Yemen and Syria, he played a key role in building Iran�s network of allied groups across the Middle East, which included Shiite militias in Iraq and groups such as Hezbollah in Syria and Lebanon.

Suleimani was a major figure in the highest levels of Iranian decision making, reporting directly to the supreme leader and overseeing military training and financing as well as weapon sales and transfers. He also took a highly public role as an Iranian symbol, often photographed on regional battlefields to underscore Iran�s support for its allies.

�He would run around the battlefield in Syria and talk to the fighters and try to boost their morale,� Tabatabai said.

But though Suleimani has a long history of orchestrating relationships with Iran�s proxy groups, he did not act single-handedly, said Suzanne Maloney, an Iran specialist at the Brookings Institution.

�He is a major figure that earned a reputation as an effective strategist ... but we have to be careful not to suggest that his death would inevitably degrade Iran�s capabilities,� Maloney said.

�This increases chance of violence,� she added. �Shiite militias in Iraq will use it to their own advantage.�

Wilkinson and Megerian reported from Washington and Etehad from Los Angeles. Times staff writers Eli Stokols and Jennifer Haberkorn in Washington contributed to this report.