Washington Post readers submitted dozens of questions this week about the U.S. attack that killed Maj. Gen. Qasem Soleimani, the aftermath of the attack and the civilian flight that Iran shot down soon after the attack.

Washington Post reporters from around the newsroom have answered some of those questions and have explained what’s at stake.

ON UKRAINE INTERNATIONAL FLIGHT 752

Q. If the evidence indicates Iran shot down the Ukrainian Boeing 737, what are the consequences? What could the United States, Canada, Germany or any other country that lost citizens do to ensure Iran is held accountable for its reckless actions. Are sanctions and military action the only two options/recourses? — Candas T.

A. On Saturday morning, Iran’s government admitted that, due to a “human error,” the military had mistakenly shot down the plane. Ukraine has called for financial compensation for the lives lost, while Canada and other countries have insisted there be a full investigation and accounting for the tragedy. Neither sanctions nor military action are likely to be pursued at this point, analysts say. Iran has said the airplane crash was not intentional and not an act of war. The most likely scenario is that Ukraine, Canada and other countries affected could in their courts sue Iran for civil liability to collect financial compensation. Criminal charges are also a possibility. Because of jurisdiction issues, it’s far more complicated and less likely. — Miriam Berger

REACTIONS BY U.S. LAWMAKERS AND OFFICIALS

Q. Which administration officials conducted the briefing that so angered Sens. Rand Paul (R-Ky.) and Mike Lee (R-Utah), and which of them refused to say that killing a head of state absent a declaration of war was not off the table for this administration? — Greg B.

A. This week’s closed-door congressional briefings featured Secretary of State Mike Pompeo, Defense Secretary Mark T. Esper, CIA Director Gina Haspel and Gen. Mark A. Milley, chairman of the Joint Chiefs of Staff, along with a battery of lawyers, who spoke with lawmakers about the intelligence that led to the strike and the administration’s legal defense of it, which rests on the 2002 authorization for use of military force that Congress passed to facilitate the 2003 Iraq invasion and the president’s constitutional right to self-defense when it comes to protecting the troops. There has been a vigorous debate in Congress about whether Soleimani really posed an imminent threat to those troops — that being a recognized exception, in the text of these war powers resolutions Democrats and a handful of Republicans are trying to get through the chambers, to the requirement that Congress authorize military actions against Iran.

During the Senate briefing in particular, several lawmakers asked the briefers to define in what circumstances, if any, the Trump administration would feel compelled to approach Congress for a declaration of war or other authorization before launching a military strike and, as Lee said, “they struggled to identify anything.” So you can assume that none of the officials said killing a head of state without a declaration of war was absolutely off the table. But senators were especially frustrated with Esper, who is the one who told them that questioning the strike and showing a lack of solidarity with the president would be damaging to troop morale — which lawmakers heard as the administration telling them, as Lee put it, “to be good little boys and girls and not debate this in public.” — Karoun Demirjian

Q. What have our generals and intelligence community said about this? Are they supportive of the action or are they pretty hush about it at this point? — Ty J.

A. No U.S. intelligence​ official has made a public statement about the strike on Soleimani. Milley, the most senior uniformed military officer, has said the strike was necessary to stop attacks by Soleimani and the United States had intelligence to support Soleimani’s intentions. — Shane Harris

THE INTERNATIONAL RESPONSE

Q. Can Iran make a complaint to the United Nations about the assassination? What has been the U.N.’s official response until now? — Marcelo V.

The United States has maintained its strike was legal as a form of self-defense. However, the U.N. rapporteur on extrajudicial executions, Agnès Callamard, has concluded that’s probably not the case: The killings “most likely violate international law incl human rights law,” she tweeted Jan. 2. “Lawful justifications for such killings are very narrowly defined and it is hard to imagine how any of these can apply to these killings.”

She added in another tweet: “Outside the context of active hostilities, the use of drones or other means for targeted killing is almost never likely to be legal.”

Q. What’s Vladimir Putin’s reaction? — Margarita M.

A. Russian President Vladimir Putin has criticized Trump’s decision to authorize the killing of Soleimani, saying the move could destabilize the Middle East. Russian Foreign Minister Sergei Lavrov has called the move illegal and counterproductive. But, as The Washington Post’s Robyn Dixon reported from Moscow, Russia “may end up benefiting from the fallout.”

“If the United States withdraws from Iraq as backlash over the killing widens, Russia could strengthen its foothold in the country — much as it did in Syria after Trump ordered a troop pullout there last fall, a step that was later partly reversed.” Dixon wrote. — Miriam Berger

MORE SANCTIONS FOR IRAN?

Q. How do sanctions work? Could you describe examples, in actual practice? — Bruce A.

There are direct and indirect ways to restrict the flow of money to people, places, institutions and governments. The Trump administration has sanctioned more than 1,000 Iranian individuals, companies and organizations since withdrawing from the 2015 nuclear deal. Then, on Friday, it announced new sanctions, this time targeting Iran’s metal industries, as well as some senior military and national security officials.

In the case of oil, the Trump administration has threatened to impose sanctions on countries that buy oil from Iran, thereby severely restricting the country’s market. Initially the United States granted some countries waivers, meaning they could buy Iranian oil without fear of an American financial reprisal. But those waivers expired in May, depressing Iran’s oil economy, as these graphs show.

Sanctions can have far reaching effects: Trying to cash-strap a government, for example, trickles down to the people, too. — Miriam Berger

THE CONTRACTOR WHO WAS INITIALLY KILLED

Q. Who was the contractor and what did he do that sent him to foreign lands? Was he a mercenary, builder or language expert? Whom did he work for? — Jenny S.

A. The American contractor killed near Kirkuk, Iraq, was 33-year-old Nawres Hamid. He was born in Iraq and became a U.S. citizen in 2017. He was married and had two boys, ages 2 and 8.

Hamid worked as an interpreter for U.S. forces in Iraq. It’s actually very common for contractors (and subcontractors) to be working on U.S. bases and for the U.S. military in Iraq (and anywhere else the United States has troops). The number of contractors, hired through private companies, aren’t included in U.S. troop counts. Despite that, they are a big part of what America’s military presence in the Middle East looks like. — Miriam Berger

DID IRANIAN PROXIES KILL AMERICANS?

Q. What proof is there that Iranian proxies killed hundreds of Americans? I thought Americans were fighting the Islamic State, which is Sunni not Shiite. — Nicole R.

A. Iranian intelligence groups provided advanced improvised explosive devices, or IEDs, and training to Shiite groups in Iraq by 2005, according to the U.S. Army’s official history of the conflict, and that was echoed by retired Gen. Stanley McChrystal, who told the New Yorker in 2013 that U.S. intelligence identified IED factories in Iran. The weapons killed at least 196 U.S. troops alone, officials have said. The Shiite militias with Iranian ties included one led by Moqtada al-Sadr, a powerful Iraqi cleric who oversaw fierce battles against U.S. troops for years in Baghdad, Najaf and other cities; he returned to Iraq in 2011 after years of self-imposed exile in Iran. — Alex Horton

Read a previous Q&A with reporters: “Does the president have to consult Congress?”