On Monday, news came out in three different reports that the US, in consultation with Turkey, was considering the establishment of a safe zone on the Turkish-Syrian border. The reported plan was billed as a sign of the US narrowing its differences with Turkey, which has long advocated a no-fly zone and a buffer zone on its border with Syria. In reality, the leaked proposal only underscores the chasm between Ankara and Washington on Syria. What’s more, it serves as another public White House announcement to Iran and to US allies that the Assad regime is off-limits.

Predictably, the White House and the Pentagon quickly shot down any impression that there was a change in US policy regarding setting up either a no-fly zone or a buffer zone. In fact, the White House had already publicly telegraphed its unwavering position on the matter ahead of Vice President Joe Biden’s trip to Turkey two weeks ago. But what was reported in the media was not a plan for a no-fly zone. Rather, reflecting the White House’s tight constraints on the discussion, it was something much smaller, and with an entirely different emphasis than what the Turks and other allies are hoping for.

Turkey had envisioned a zone that would provide protection to “areas with populations over a certain density,” especially covering the stretch from Kobane westward to Idlib and Afrin. Instead, according to The Washington Post, what’s being considered only covers a narrow belt along the border north of Aleppo eastward toward Kobane. And it’s not just the size of the zone that’s scaled down in the American proposal; its purpose is also narrowed drastically. It is meant to push back the Islamic State (ISIS) from the area, using US airpower, possibly in cooperation with the Turkish Special Forces Command, who would support Syrian rebels to hold the territory. The Assad regime, meanwhile, would not be touched in any way. In fact, one report claimed the administration would communicate quietly to the regime that it should stay away from the zone.

All US allies have sought to change the White House’s posture toward Bashar Assad — they want him gone, as President Obama himself said in August 2011. They have failed consistently. Senior administration officials who also sought such a change have not fared better. Former Secretary of Defense Chuck Hagel criticized the White House’s ambiguous position on Assad, and he was pushed out. Now General John Allen, President Obama’s special envoy for the coalition against ISIS, who is leading the negotiations with Ankara, is reportedly facing White House opposition to any shift in policy. This is the case even when what’s being proposed to the Turks is well within the parameters of White House priorities and limits.

The uncompromising rejection of any confrontation with Assad is the first reason why the leaked proposal is a non-starter. Even if Turkey were to accept such a scaled-down plan, advertising publicly that the US would only go after ISIS and would not target the regime is an invitation for Assad to target the zone and put the Turks on the spot. Drawing on Obama’s record in Syria, Assad would safely calculate that Washington would not come to Turkey’s defense and would reject any escalation. Sure enough, the Post reported that US officials are “distrustful of Turkey’s desire” to draw them “into a direct confrontation with Assad.” In other words, if he had any doubts, Assad now understands he enjoys de facto US protection.

Regardless of the Turkish response to this latest leak, the Post noted that the US president was briefed on the outline of the plan last Wednesday. He hasn’t approved it yet. Bloomberg View added that the White House has not yet formally considered it. “There is nothing imminent,” a US official told the Post.

And that’s one main point of this exercise. By publicly airing an internal policy discussion involving negotiation with an ally, the White House is signaling, to the Iranians especially, that it remains opposed to going after their Syrian asset. Also, whatever the US might consider would be strictly confined to targeting ISIS — which is fine with Iran, having itself targeted ISIS positions in Iraq this week.

It’s worth recalling that the Iranians have publicly warned Washington against expanding the parameters of the campaign against ISIS to include targeting Assad. The White House has dutifully reassured them that it remains onside, dismissing all proposals that carry even the risk of confrontation with Assad. And it’s not just the Turks that are being brushed aside: the French, too, back the creation of safe zones. However, as French Foreign Minister Laurent Fabius pointedly observed last week, “There are quite a few people to convince, the Americans of course.”

The word in the White House is “de-escalation.” This means that instead of working with allies to extend protection to Syrian civilians and to constrain Assad’s killing machine, the White House is more concerned with publicly signaling that its priority is to avoid any clash with Assad.

Tony Badran is a research fellow at the Foundation for Defense of Democracies. He tweets @AcrossTheBay.