Last July, in the midst of the presidential election campaign, Donald Trump declared in an interview that he was "a big fan of the Kurds." Speaking about the fight against ISIS on the ground in Syria, Trump said he hoped there was a way to get the Kurdish forces, which have been supported by the U.S. for the last two years, to join forces with their bitter enemy, the Turkish government.

"I’m a big fan of the Kurdish forces. At the same time, I think we could have a potentially very successful relationship with Turkey. And it would be really wonderful if we could put them somehow both together," Trump explained. When asked how he would do that, he answered – "meetings. We will have meetings very early on," without providing any further details.

Entering his fourth week in the White House, however, it seems like Trump is beginning to find out that when it comes to the fight against ISIS, the U.S. might have to make a hard choice between the Kurds and Turkey. In north-eastern Syria, Kurdish forces are currently advancing towards Raqqa, a city that has been ISIS' headquarters ever since 2013. They're doing so with the support of American airstrikes and intelligence, and to the dismay of the Turkish government, which is worried about its own domestic problems with a large Kurdish minority in the south of the country.

The group leading the fight against ISIS on the ground is The Syrian Democratic Forces (SDF), a coalition that includes the largest Kurdish organization in Syria, the People's Protection Units (often referred to as YPG) and a number of Arab, Assyrian, and other ethnic groups. The SDF was founded in 2015 and has had more success than any other group thus far in fighting ISIS within Syria. Their ultimate goal is to establish an autonomous region in northern Syria, where there is a large concentration of Kurdish population. Turkey, meanwhile, sees the SDF as a front organization that, under the cover - including in its ranks some non-Kurdish fighters - is in fact working to advance the agenda of the PKK, a Turkey-based Kurdish terror organization that is fighting for Kurdish autonomy.

Turkish president Recep Tayyip Erdogan has protested in the past over the Obama administration's support of the SDF, yet his promises to create an alternative, Turkey-supported force in Syria that will take down ISIS, have so far failed to materialize.

A delegation representing the SDF spoke with Haaretz recently during a working visit to Washington, D.C. aimed at convincing the new administration to adopt the group's plan for an autonomous region in northern Syria. "Our message to President Trump is that he needs to support the people who are right now fighting against ISIS on the ground in Syria," said Ilham Ehmed, the co-president of the group's political arm. She also told Haaretz that "we expect not only military support, but also political support. It's time for the United States to start thinking about the day after we defeat ISIS. The best plan is a federal Syria, including a democratic, pluralistic and free autonomous region in the areas where the SDF is now fighting ISIS."

The conversation with Ehmed and her colleagues took place on Capitol Hill, where the delegation was meeting members of Congress to present their vision for defeating ISIS and stabilizing Syria in the Trump era. "The Obama administration helped the Kurds at a very critical point, during the battle of Kobane," Ehmed added, referring to a Kurdish town in northern Syria that was under siege by ISIS for months in 2014, and eventually managed to push back the Islamist organization. "What we want to ask from the Trump administration is to go further and recognize an autonomous region."

Ehmed and the other members of the delegation entered the U.S. before Trump signed his executive order banning people from Syria and six other Muslim-majority countries from entering the United States. When asked about it, she replied that this was "an internal decision for the U.S. people to discuss" and that "we understand why the U.S. needs to have its own security measures." The important thing, she concluded, "is how to stabilize the situation in Syria. We propose establishing an independent, secure and democratic entity that will lead the way."

The SDF takes pride in being "the only group in Syria that includes members of all the countries' religions and ethnic groups," as Ehmed puts it, but the Turkish government isn't sold on this description. Erdogan, who spoke with Trump on the phone last week for the first time since the presidential inauguration, believes that the group is working to create an independent Kurdish de-facto state in northern Syria, and since such a state would sit right next to Turkey's southern border, where there is a large concentration of Kurdish population, he is strongly opposed to the idea.

Erdogan tried to persuade the Obama administration to minimize its support of the SDF, and offered to instead create an Arab-led coalition against ISIS, with Turkey's support. It's what he will likely also try to offer Trump's new administration. "These talks have been on-going for years, but have never amounted to much," says Dr. Aaron Stein, a senior fellow at the Atlantic Council and an expert on the U.S.-Turkey relationship. "There is not much interest in the U.S. military for a joint offensive and Turkish promises to generate a large Arab force have never materialized."

Stein believes that Erdogan has good reasons to worry about the incoming administration, not only because of Trump's past statements of support for the Kurds. American support for an autonomous region in the north, he told Haaretz, seems very likely to eventually happen: "I think it is very likely. The writing is on the wall for an eventual Russian-U.S. rapprochement in Syria, and that will entail drawing lines on a map, and decentralizing elements of the Syrian state. Iran and the [Assad] regime will play spoiler, but history tells us that both of those actors can reach agreements with the PKK."

As for Trump's hope of getting Turkey and the Kurds to work together, Stein is very skeptical about it ("No," he replied to a question on whether Trump can get both sides satisfied). So is Aykan Erdemir, a former Turkish member of parliament who is currently a senior fellow at the Washington-based Foundation for Defense of Democracies. "The Obama administration tried to pursue a balancing act between Ankara and the Syrian Kurds. It is difficult to argue that U.S. tactics were successful. U.S.-Turkish relations continued to deteriorate over the years. The Trump era might be marked less by opaqueness and balancing than bold and frank messages and actions. Ultimately, Erdogan might have to adapt to the new reality on the ground whether he likes it or not."

Erdemir told Haaretz that he also thinks "the future of Syria will be marked by decentralization and self-governing entities. This is the de facto situation on the ground, and we'll see whether there might one day be a constitutional framework to formalize the status of existing status quo. I think the U.S. administration would be sympathetic to such an arrangement."

Erdogan, however, is expected to at least try and put up a fight, before accepting this reality on his border. "Ankara sees a contiguous Kurdish entity in northern Syria as an existential threat," Erdemir explained. "Erdogan is already very concerned about the existing relationship between the U.S. and the Syrian Kurds. Any further deepening of that cooperation would certainly lead to strong criticism from Ankara." Last week, after the Erdogan-Trump phone call, CIA director Mike Pompeo made a brief visit to Ankara to discuss the fight against ISIS. The hastily arranged visit gave hope to some in Turkey that the Trump administration would at least consider decreasing its support of the SDF, and increasing instead its cooperation with the Arab forces supported by Turkey. Yet at a time when the SDF is only miles away from Raqqa, they have a strong argument to make in front of the administration when asking for more support from the new president.