President Obama’s announcement Wednesday that he is sending 450 more military advisers to Iraq highlights the central dilemma of his faltering strategy there: how to shore up the country’s fragile government without being pulled more deeply into a war he never wanted.

With few good options, Obama’s plan amounts to a decision to stay the course.

Administration officials say the troop increase — the second since U.S. troops returned to Iraq last year — isn’t intended to produce quick battlefield victories.

Rather, the additional troops are being sent to aid Prime Minister Haider al-Abadi’s outreach to disaffected Sunnis and bolster the Iraqi army, whose feckless performance has left the Iraqi leader vulnerable to challenges from Shiite hard-liners more closely aligned with Iran. A weakened Abadi, U.S. officials fear, would strengthen the position of Shiite Iran, which has cast itself as Iraq’s only effective partner in a largely sectarian war with the Sunni-dominated Islamic State.

“The trend lines [for Abadi] are not good,” said Doug Ollivant, a former military planner in Baghdad and senior fellow at the New America Foundation. “He needs a win — and preferably a string of two or three of them.”

Obama’s announcement Wednesday will put American service members inside the Iraqi headquarters overseeing the offensive to recapture territory lost last month to the Islamic State in Ramadi and surrounding Anbar province.

In a reflection of the president’s conviction that U.S. military power can’t win the war, the plan won’t allow U.S. advisers to move closer to the front lines where their support could bolster the morale of Iraqi troops fighting to retake the strategically important city of Ramadi, west of Baghdad.

Neither does the new deployment include forward air controllers, who could direct airstrikes from U.S. bombers. It also does not envision the use of Apache attack helicopters, which are among the most lethal weapons in the U.S. arsenal in urban combat.

Taken together, the steps and limits show Obama’s deep-seated conviction that only the Iraqis can resolve a fight driven by Sunni feelings of anger, persecution and abandonment at the hands of the Shiite government in Baghdad. The president’s ­focus, for now, is on forcing the Iraqis to solve their own problems. He is also determined to keep Americans — who haven’t suffered a single combat casualty in the fight against the Islamic State in Iraq and Syria — out of harm’s way.

“The loss of Ramadi needed a response,” said Brian Katulis, a senior Middle East analyst at the left-leaning Center for American Progress. “I see this as more of a tactical shift. The focus is still on getting the Iraqis to pull their own weight. It is important but largely tactical.”

Senior White House officials on Wednesday emphasized the immediate benefits that hundreds of new advisers would bring to the fight against the Islamic State. The American troops inside the Iraqi headquarters will provide intelligence about enemy movements and ensure that Baghdad responds to shortages of weapons, fuel and food in the field and help commanders ensure airstrikes happen more quickly.

The White House also hopes the additional U.S. help will steady Iraqi commanders who have ordered retreats even when their forces have vastly outnumbered their Islamic State enemies.

“When we’re fused with them and advising and assisting, we’re able to kind of see a little better and — buck up the ranks,” said Brett McGurk, a deputy assistant secretary of state overseeing Iraq policy. “I think this will have a fairly dramatic effect. . . . Sometimes the enemy is not as strong as they pretend to be.”

In the attack on Ramadi, ­Islamic State fighters sowed panic by setting off suicide truck bombs and ambushing Iraqi troops from multiple directions. Even though the Iraqis outnumbered their attackers in some areas by as many as 40 to 1, they still fled, said senior military officials. Their collapse has provoked widespread frustration in the Pentagon, where U.S. military officials complain of repeated Iraqi leadership failures, poor discipline and ineffective systems for keeping the military running.

The problem, say these military officials, isn’t that Islamic State fighters are especially good but that Iraqi army forces are so bad.

“There is a sense that the whole thing will just take more time,” said a senior U.S. official who noted that the administration is only eight months into a three-year plan for Iraq and that the Islamic State is dealing with its own problems.

American attack planes have killed thousands of the group’s fighters since last summer, U.S. officials said. To hold on to power in the areas it controls, the Islamic State depends on brutal repression and has struggled in recent weeks even to feed its own people, U.S. officials said.

U.S. officials are hoping that as the months pass, Sunnis, who have passively supported the ­Islamic State, will turn on the group. A major focus for the new trainers headed to Iraq will be forging ties with Sunni tribes that were essential to the defeat of Sunni extremist groups inside Iraq in 2007 and 2008. Many of those Sunnis, who fought alongside U.S. forces during the latter days of the U.S. occupation, felt betrayed when the United States left in 2011 and then-Prime Minister Nouri al-Maliki, Abadi’s predecessor, drove them from power and arrested their leaders.

“It’s critically important to get the Sunnis in the main security forces,” said Elissa Slotkin, assistant secretary of defense for ­international security affairs. “That’s another reason we want U.S. forces on the ground, to help facilitate that conversation.”

More than a dozen years of war have made that conversation increasingly difficult. Iraq’s Sunni population today is deeply fractured, demoralized and, in some cases, willing to embrace the Islamic State over the Shiite-led government. While many Sunnis were happy to see Maliki step down last year, they are already growing disillusioned with ­Abadi.

Khalid al-Mufriji, a Sunni Arab lawmaker, said Abadi’s government continues to sideline many of the country’s most well-known Sunni politicians and is resisting steps to devolve power to the provinces. “We remain still far from addressing Sunnis’ demands,” he said during a visit to Washington this week.

Republicans, meanwhile, seized on Obama’s plan, saying it wouldn’t do enough to heal the country’s sectarian fissures. “Disconnected from a broader coherent strategy, it is not likely to be any more successful than our previous efforts,” said Rep. Mac Thornberry (R-Tex.), chairman of the House Armed Services Committee.

Healing those sectarian wounds could take years. Earlier this week, Obama praised Abadi for his commitment to a “political agenda of inclusion” even as he acknowledged that the premier’s outreach to disaffected Sunnis only weakened his position with his Shiite base.

“He’s inheriting a legacy of a lot of mistrust,” Obama said. “He’s having to take a lot of political risks.”

The U.S. troops are expected to arrive at Iraq’s Taqaddum air base outside Ramadi in the next few days. It wasn’t clear how long they would stay.

Obama’s modest troop boost amounted to an acknowledgment that the United States was still in for a long war, one that is likely to extend well beyond his presidency.

Until then, U.S. military officials said they will rely on targeted counterterrorism raids by Special Operations forces and airstrikes to minimize the threat to the U.S. homeland.