The Biden administration took two potentially critical steps toward ending Saudi Arabia’s devastating war in Yemen on Thursday. First, national security advisor Jake Sullivan announced that it is ending US support for “offensive” Saudi military operations in Yemen. Second, Sullivan also announced the appointment of career foreign service officer Timothy Lenderking, previously a deputy assistant secretary in the State Department’s Near East Bureau, as a special Yemen envoy.

Ever since the Obama administration made the ill-advised decision to back the Saudi war effort against Yemen’s Houthi rebels back in 2015, the United States has owned substantial responsibility for what has become the greatest humanitarian catastrophe in the world. Tens of thousands of people or more (it’s virtually impossible to know how many at this point) have been killed violently in the conflict, with countless more wounded. Millions have either already died from or been left to struggle with rampant preventable disease (including COVID-19, whose effects have been similarly impossible to track, given the war and Yemen’s shattered public health infrastructure) and the lack of basic resources like food, medicine, and clean water.

Most of this suffering has been brought about by a brutal Saudi-led blockade and air campaign targeting Houthi-controlled northern Yemen, both of which have been made possible by US support. As a result, the United States has been liable in myriad Saudi actions that appear at least on their face to meet the definition of war crimes.

In this context, any rethinking or diminishment of that US support is a positive thing. Likewise, the appointment of a special envoy signifies a new US effort to push for a diplomatic end to the Yemen war, instead of leaving any diplomatic efforts up to the Saudis as the Trump administration did.

Lenderking doesn’t seem to be that well known, but he is familiar with the region and with the Yemen war in particular, and the fact that he is a career diplomat is probably a mark in his favor — at least compared with the background of another recent US envoy.

Without being unduly skeptical, however, until the administration fills in the details behind this announcement, it will be difficult to know just how positive these developments are. In particular, the administration should explain exactly what it means by “offensive” operations.

Distortions of the terms “offensive” and “defensive” with respect to warfare are almost as old as war itself, though we don’t need to dip too far back into the past to find egregious examples like Turkey’s 2016 invasion of northern Syria under the moniker “Operation Euphrates Shield,” Israel’s 2014 war in Gaza under the name “Operation Protective Edge,” or even the 2003 US invasion of Iraq, which the Bush administration characterized as “preventive.” We don’t even need to leave the conflict in Yemen, which the Saudis have long been describing as “defensive” despite substantial evidence to the contrary.

In a speech at the State Department on Thursday afternoon, after Sullivan’s announcement, Joe Biden pledged that the United States would “continue to support and help Saudi Arabia defend its sovereignty, its territorial integrity, and its people.” Unless his administration explains clearly what it means by “offensive” versus “defensive” operations, we simply do not know just how big a change Thursday’s announcement represents.

Will the United States stop providing logistical support for the Saudi blockade and/or its air strikes? What if the Saudis claim those operations are necessary to defend the kingdom from Houthi missile and drone strikes?

Similarly, the administration should provide more information about its recent decision to suspend arms sales to the Saudis and to the United Arab Emirates, whose leaders are also culpable in the Yemen disaster, though they’ve stepped down their overt involvement in the conflict since the middle of 2019. The freeze seems intended to pressure the Saudis to negotiate, but the administration should outline what it expects the Saudis and Emiratis to do in order to resume those sales.

In his speech, Biden spoke of suspending “relevant” arms sales, suggesting the freeze isn’t total. More clarity here would also be welcome.

There are other concerns. The administration says it intends to continue US military operations in Yemen (primarily drone strikes) against Al Qaeda in the Arabian Peninsula, and it’s safe to say that also applies to Islamic State elements that are active in Yemen. US “counterterrorism” (CT) operations are inherently destabilizing, and their continuation in Yemen is a potential roadblock to the peace process. However, as Win Without War’s Kate Kizer wrote on Twitter after the announcement, ending US involvement in the war “opens the door” for a new debate on that CT mission and its effects.

The US State Department also continues to list the Houthis as a “Foreign Terrorist Organization,” a dubious designation made late in the Trump administration that threatens to undermine peace efforts, prevent the commercial importation of basic goods into Yemen, and cripple the ability of humanitarian relief agencies to operate in Houthi-controlled parts of the country. The Biden administration says it is “reviewing” the designation, and it has issued a blanket waiver to permit commercial and humanitarian work in the meantime, but aid organizations say that’s not enough. Hopefully the administration, having taken a first step toward peace, will rescind this designation as soon as possible.

Again, these are all caveats — unanswered questions surrounding what has the potentially to be a dramatically positive change in US foreign policy. But they should not diminish the significance of what the administration announced on Thursday.

After Biden’s election in November, I wrote that his immediate approach to the crisis in Yemen would say much about the kind of foreign policy he intends to pursue. If the Biden administration does take meaningful action to end US involvement in Yemen and to pressure Saudi Arabia to negotiate an end to that war, it will not only mean a new dawn for the Yemeni people. It will have positive implications for the shape of US foreign policy moving forward. It suggests that candidate Biden’s campaign rhetoric about undertaking a long overdue reassessment of Washington’s toxic codependent relationship with the Saudis might actually be substantive.

It also suggests that despite Biden’s long history as a warmonger, because of the changed conditions his administration is operating in, he may be responsive to the concerns of and pressure from human rights and anti-war organizations, and that their mobilization has the potential to impact US policy decisions. After the past few years, both would be very welcome changes.