For the second time in barely a year, Donald Trump has reversed himself and attacked the Syrian regime of Bashar Assad in stated retaliation against a chemical weapons attack.

But the very fact of the strikes, so soon after a volley that the Trump administration had said would not portend greater punitive measures against Assad, raises immediate questions about what they will achieve—particularly since Assad has a nuclear-powered patron at his airfields, in his port and over his territory: Russia.

The confusion began about an hour after Trump’s announcement of the opening of a “sustained” campaign against the regime. That’s when his secretary of defense, James Mattis, announced, “Right now, this is a one-time shot, and I believe that it sent a very strong message to dissuade him, to deter him from doing this again.” Mattis added that there was no intention to “expand that target set.”

Trump framed the strikes—against three targets, a scientific research center and two so-called chemical weapons storage facilities—as punishment and check against the further use of chemical weapons, which the president said were “uniquely dangerous not only because they inflict suffering, but because even small amounts with unleash widespread devastation.”

“The purpose of our actions tonight is to establish a strong deterrent against the production, spread and use of chemical weapons,” Trump added.

But again, the pronouncement appeared to be undercut by Mattis. He noted that the U.S. had no definitive proof that the banned nerve agent sarin was used in the most recent chemical attacks. (Rather, the U.S. is “not ruling out sarin,” he said.) Chlorine, the industrial chemical widely used by the Assad regime in its murderous fight against Syrian rebels, requires no special production facilities.

“ The confusion began about an hour after Trump’s announcement of the opening of a ‘sustained’ campaign against the regime. That’s when his Secretary of Defense, James Mattis, announced, ’Right now, this is a one-time shot.’ ”

Allies of the president and White House officials wanted to emphasize that—as news of further intervention against the Assad regime trickled in on Friday evening—this is not the inauguration of Trump The Nation Builder. Earlier this week, multiple sources within and without the administration, who have spoken to President Trump in days since the reported chemical attack in Syria, told The Daily Beast that the president’s desire to leave Syria as “soon” as possible has not fundamentally changed.

Though Trump quickly resolved to punish Assad’s forces after news of a chemical atrocity broke, the U.S. president has told associates and aides that it is still his wish to extract American involvement in the astonishingly brutal civil war after ISIS is defeated in the country—to “let others deal with the mess,” as the president has previously phrased it in private conversation.

“[President Trump] wants to send a strong message to Assad, Putin, Iran,” a Trump confidant said. “He still strongly prefers we get the hell out of there as soon as it can be done, if not sooner even.”

In a sense, the mixed message wasn’t all that different from the one Trump sent when he ordered an April 6, 2017, Tomahawk missile strike on the Shayrat airfield that the Assad regime was said to use to stage a sarin attack on Khan Sheikhoun. It reversed four years’ worth of antipathy for wading into the brutal Syrian civil war, as well as occasional expressions of comfort with Assad as aligned with him against Islamic State. It also reaped him the best media reviews of his presidency from vacant pundits.

Nearly immediately, his security advisers signaled that they sought no further action against Assad. It was “singular, against the chemical-weapons use,” Mattis said on April 11, 2017.

H.R. McMaster, then Trump’s national security adviser, also defined the objectives of the strike minimally. After reports emerged that the Syrians had, within days, repaved the airfield, McMaster told Fox News, “I mean, that’s not what the objective was, to take out the airfield forever. The objective was to send a very strong political message to Assad.”

Trump all-but-acknowledged tonight that this objective was not met. “One year ago, Assad launched a savage chemical weapons attack against his own innocent people. The United States responded with 58 missile strikes that 20 percent of the Syrian air force. Last Saturday, the Assad regime again deployed chemical weapons to slaughter innocent civilians near the Syrian capital,” he said.

But it wasn’t the only time. In the year since the 2017 Tomahawk strikes, Assad launched dozens of chemical attacks on Syrians, starting last July. That was also the month that the Trump administration began signaling that it was willing to acquiesce to a Russian-led political process that would wind down the war with Assad in power. Earlier this month, Trump re-reversed himself, and publicly expressed a desire to expeditiously pull U.S. forces out of Syria.

Within days, Assad’s forces assaulted the Damascus suburb of Douma in an apparent chemical attack, leaving at least 70 dead and 500 exposed.

“ [President Trump] wants to send a strong message to Assad, Putin, Iran... He still strongly prefers we get the hell out of there as it can be done, if not sooner even. ” — Trump confidant

Trump called it an “evil and despicable attack” which “left mothers and fathers, infants and children thrashing in pain and gasping for air. These are not the actions of a man. they are crimes of a monster instead.”

And Trump’s message included a warning to Moscow and Tehran, which he said were the “two governments most responsible for supporting, equipping and financing the criminal Assad regime. To Iran and to Russia, I ask what kind of a nation wants to be association with the mass murder of innocent men, women and children?”

“In 2013, President Putin and his government promised the world they would guarantee the elimination of Syria's chemical weapons. Assad's recent attack and today's response are the direct result of Russia failure to keep that promised,” the president added. “Russia must decide if it will continue down this dark path or if it will join with civilized nations as a force for stability and peace.”

How far Trump is willing to go to push those patrons may be the central question of the campaign.

“H ow far do you have to go to reach that goal [of deterring chemical attacks] without running into the probability or risk of a much more dangerous confrontation? Given the presence of Russia, the presence of Iran, the state of tension [is] higher than it was a year before,” said Rob Malley, a former senior Mideast aide on Barack Obama’s National Security Council and the president of the International Crisis Group.

That’s because Russia’s sponsorship of Assad boxes the Trump administration into a strategic corner. Another one-off strike, even on a larger scale than last year’s, can be absorbed by the regime, accomplishing little to nothing.

Trump himself seemed to admit this on Friday night. “We are prepared to sustain this response until the Syrian regime stops its use of prohibited chemical agents,” the president said.

But Trump’s approach—if that’s the one his generals actually take—has risks, as well. A broader military campaign risks a potentially catastrophic confrontation with the Russian air force. At most, the U.S. can continue to launch strikes to limited effect and hope that they don’t end up crossing Russian red lines, a gamble more costly for the U.S. than for the Assad regime it means to deter.

“Another volley of Tomahawks by themselves will not move the needle,” said retired Adm. James Stavridis, a former NATO commander and now dean of the Fletcher School at Tufts University. “The best use of TLAMs [Tomahawks] is to knock out Syrian air defense systems to open a path for a significant long range air strike with heavy bombs and take out real Syrian capability. And hopefully avoid collateral damage that kills Russians—a tricky operational mission.”

Last year’s missile strikes yielded harsh Russian rhetoric and little else. In advance of this year’s, the Russians appeared to up the stakes. A Russian diplomat in Lebanon threatened not only to shoot down incoming U.S. missiles but to attack the warships that launched them. (It’s probably an empty threat, but it’s a threat nonetheless.) According to Syrian opposition media, Assad’s forces were said to be moving fixed-wing aircraft and helicopters to the Khmaiman air base, co-locating them with Russian forces whom U.S. warplanners would be loath to hit without tempting escalation.

“The general risk of actual military conflict between Russia and the U.S. are the highest since the end of the Cold War, and the current situation is a spike in that dangerous situation,” said Stavridis.

“These are very unpredictable actors,” Malley said. “It would be wise to be cautious and not to trip into something that we don’t intend to trip into.”

—with additional reporting by Noah Shachtman