President Trump has approved a plan to arm Syrian Kurds so they can participate in the battle to retake Raqqa from the Islamic State, a strategy that has drawn deep opposition from Turkey, a NATO ally.
American military commanders have long argued that arming the Y.P.G., a Kurdish militia fighting alongside Syrian Arab forces against the Islamic State, is the fastest way to seize Raqqa, the capital of the militants’ self-proclaimed caliphate.
And Mr. Trump, who made fighting Islamist militants a priority during his campaign, again showed the high regard he has for Pentagon generals by endorsing their advice when faced with a policy dilemma.
Turkey has objected vociferously to such a move, raising fears of a backlash that could prompt the Turks to curtail their cooperation with Washington in the struggle against the Islamic State.
A high-level delegation of Turkish officials was informed of the decision by Lt. Gen. H. R. McMaster, Mr. Trump’s national security adviser, when they visited the White House on Monday, and the Pentagon announced the move on Tuesday.
Mr. Trump’s decision on arming the Syrian Kurds comes as Iraqi forces, backed by American and allied air power and artillery, are making headway in Mosul. American military commanders have argued for simultaneous offenses in Raqqa and Mosul so the Islamic State would be forced to defend multiple fronts.
The president’s decision also comes as his top advisers recommended sending 3,000 to 5,000 more American troops to try to break a stalemate in another hot spot: the 15-year war in Afghanistan.
Dana W. White, the chief Pentagon spokeswoman, said in a statement that the arming was necessary to ensure that Raqqa could be taken “in the near future.”
“Yesterday, the president authorized the Department of Defense to equip Kurdish elements of the Syrian Democratic Forces as necessary to ensure a clear victory over ISIS in Raqqa, Syria,” she said, using the name of the umbrella group for Arab and Kurdish fighters battling the Islamic State, also known as ISIS or ISIL.
Ms. White added that the United States would take steps to ensure that Turkey did not face “additional security risks.”
There was no immediate comment from the Turkish government, which considers the Kurdish force to be terrorists, and it remains to be seen whether the assurances the Trump administration is offering the Turks will be sufficient to ease the concerns of President Recep Tayyip Erdogan, who is scheduled to meet with Mr. Trump in Washington next week.
The weapons that the United States will provide Kurdish and Arab fighters in the anti-Islamic State coalition include heavy machine guns, mortars, anti-tank weapons, armored cars and engineering equipment.
American military officials have said that weapons are needed to help the lightly armed Kurdish and Arab fighters cope with urban warfare in Raqqa against unyielding Islamic State militants who are equipped with car bombs and even some tanks they captured from the Syrian Army.
To address Turkish concerns that the arms might be used against their forces one day, the supply of weapons and ammunition will be limited to what the Kurds and Arab fighters need to carry out specific operations, American officials said.
After the battle is over, an effort will be made to retrieve any excess equipment. American advisers will also monitor the weapons that are provided to the Kurds and will cut off the supply if they discover that they are being smuggled for use elsewhere or misused, United States officials said.
To further mollify the Turks, most of the fighters who will be involved in the assault on Raqqa are expected to be Arabs, and the Pentagon said the Y.P.G. would not occupy the city after Islamic State fighters had been ousted. “Raqqa and all liberated territory should return to the governance of local Syrian Arabs,” Ms. White said. “We do not envision a long-term Y.P.G. presence.”
The United States has long worked with the Y.P.G., or People’s Protection Units, under the umbrella of the Syrian Democratic Forces. The American military has always emphasized that those forces includes Arab fighters, who make up nearly half of the total force and most of the fighters near Raqqa. But the Y.P.G. is generally considered to have the most experienced and battle-hardened fighters.
The Turkish government has long insisted that the Kurdish militia is closely linked to the Kurdistan Workers’ Party, a separatist group known as the P.K.K. That group is listed by Turkey, the United States and Europe as a terrorist organization.
Any hope that Mr. Erdogan might soften his position on arming the Y.P.G. after winning a referendum that gave him vast powers appeared to fade last month after Turkish warplanes carried out an airstrike against the Syrian Kurds.
According to Turkish news reports, the officials who met with General McMaster on Monday included Gen. Hulusi Akar, the commander of the Turkish armed forces; Hakan Fidan, Turkey’s intelligence chief; and Ibrahim Kalin, the presidential spokesman. Their mission, the Turkish news media reported, was to talk the Trump administration out of arming the Kurds. Instead, they were informed that the decision had already been made.
Syria analysts, as well as current and former senior American officials, said Mr. Trump’s decision was not surprising given the military’s insistence on arming the Kurds for the impending battle for Raqqa, but they warned it could damage broader relations with Turkey.
“This decision was probably necessary if the coalition to defeat the Islamic State was to take Raqqa without huge numbers of U.S. troops being directly involved,” said Andrew Exum, a former top Pentagon Middle East policy official who served as an Army Ranger. “But this decision — to arm a group closely associated with a foreign terrorist organization, and one that has waged a decades-long insurgency against the Turkish state — will likely reverberate through U.S. relations with Turkey for decades to come.”
James F. Jeffrey, a former United States ambassador to Turkey and a fellow at the Washington Institute for Near East Policy, agreed that the decision would add to the tension in American-Turkish relations. “We’re putting Turkey in a very difficult position,” he said.
Syrian Kurds, however, hailed the move. Alan Hassan, reached via internet messaging in Qamishli, in northeastern Syria, part of the de facto semiautonomous zone Kurds have carved out during the Syrian war, said that Mr. Trump’s decision gave new legitimacy to an existing partnership with the Y.P.G.
“In the beginning, American support was secret,” he said. “Now it is public. The relationship has changed from undeclared to declared.”
Former President Barack Obama also favored arming the Kurds, although divisions among his aides were so pronounced that he did not come to that view until his last week in office. During his administration’s deliberations, American diplomats in Ankara warned of a possible Turkish backlash, while military officials insisted that the Y.P.G. was the only option if Raqqa was to be taken in the coming months.
Gen. Joseph L. Votel, the commander of American forces in the Middle East, has acknowledged the challenges of dealing with two pivotal allies in the fight against the Islamic State in Syria who essentially loathe each other — the Turks and the Syrian Kurds.
But General Votel and senior American counterterrorism officials have said it is essential to rout the Islamic State from its stronghold, principally to weaken its ability to plan, direct and enable terrorist plots against the West.
In recent weeks, analysts said, the Islamic State has tried to slip some of its senior planners and operatives out of Raqqa before the battle to maintain essential functions like command and control, recruiting, handling of finances and the ability to help carry out plots against the West.
That is one reason that even as the American-backed Syrian Kurdish and Arab forces have increasingly tightened a noose around the city, and the coalition has pummeled it with airstrikes, allied fighters have also struck targets south of Raqqa, near Deir al-Zour and Mayadeen, where many of the senior Islamic State members have fled.
Anne Barnard contributed reporting from Antakya, Turkey.
©2017 The New York Times News Service