The volley of Israeli missiles that slammed into a government compound in central Tehran last Saturday morning was by any military standard a successful opening strike by the United States and Israel as they went to war with Iran.

The blasts killed Iran’s supreme leader, Ayatollah Ali Khamenei, as well as a cadre of other senior military and intelligence officials. The war’s first salvo left Iran without many of its top commanders to lead the response.

The reckoning, it turned out, was more complicated. The Israeli strike also killed another group of Iranian officials who had been meeting in a different part of the compound. Among them were people the White House had identified as more willing to negotiate than their bosses, and who might help bring a swift end to the conflict, according to American officials.

The strike on the compound in Tehran was emblematic of the muddled reality of the war’s first week: a withering air campaign by American and Israeli forces against an overwhelmed enemy, but few answers about what victory might look like. Iran, its government still in place, has remained defiant and expanded the battlefield across the region, inflicting the first American casualties of the conflict.

Even as senior administration officials in the United States spent the week trying to narrowly cast the war’s goals around denying Iran any chance of gaining a nuclear weapon, President Trump has bounced between wildly divergent explanations for what he hopes to achieve.

In his first message after the war began, Mr. Trump called for a mass uprising in Iran against the country’s leaders. In subsequent days, with little evidence that Iranians were moving to overthrow their own government and with intelligence reports concluding that the clerical regime would likely hold on to power, he indicated he cared little about Iran’s future after the military campaign ends.