On January 2, in a long-awaited move, the Palestinian Authority formally submitted its application to the UN secretary general to join the International Criminal Court. Membership in the ICC is an important step, as the Court will now be able to investigate and prosecute serious war crimes committed by Israelis (as well as Palestinians) on Palestinian territory.

The move was also unexpected, in view of the fact that until now, the PA’s policy has been to use the threat of membership as leverage in negotiations with Israel. The PA did this several times over the past two years in an attempt to get Israel to stop settlement construction. Even after the PA finally announced last July that it would sign the Rome Statute (the treaty that established the ICC), it waited until the end of the year before formally submitting the application. During that period it used the threat of membership to try to extract Israeli concessions, first during Gaza cease-fire negotiations in the summer, and then in the hope that it would persuade the UN Security Council to support a resolution specifying a deadline for the end of the Israeli occupation.

The defeat of that resolution on December 30 was the last straw. The PA was particularly angry at US tactics used to thwart it—Washington reportedly managed to persuade Nigeria half an hour before the vote to withdraw the support it had promised. At a deeper level, though, the PA’s move was the result of years of pressure from the Palestinian public to hold Israel accountable for its crimes, especially after its brutal summer assault on Gaza. There was strong pressure on PA President Mahmoud Abbas in particular, including from members of his inner circle, such as chief negotiator Saeb Erekat.

Joining the ICC is undoubtedly a positive development in the Palestinian pursuit of legal accountability for Israeli crimes. The ICC prosecutor will be able to open investigations despite the fact that Israel is not a member of the Court. The Court’s jurisdiction will cover any crimes committed just over sixty days after the date of Palestine’s accession to the Rome Statute, as well as past crimes going back at least to June 13, 2014, since the PA also submitted to the ICC on January 1 a declaration accepting the Court’s jurisdiction from that date onward.

Nor would an ICC investigation necessarily be limited to crimes committed in a narrowly military context, such as during the recent attack on Gaza. It could also cover crimes that occur during Israel’s occupation of Palestinian territory, such as the construction of settlements, and could even call into question the overarching nature—and therefore the legality—of Israel’s occupation regime.

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But none of this is as straightforward as it seems. To start with, there are several legal obstacles to a successful prosecution. Still to be resolved is the thorny question of when the ICC’s jurisdiction over Palestine begins—in 2002, when the Rome Statute first came into force, or only after 2012, when the UN upgraded Palestine’s status? Another difficulty is that the ICC is only allowed to prosecute crimes of “sufficient gravity.” It is unclear at what point crimes that occur gradually, such as settlement construction, reach a sufficient level of “gravity” to merit prosecution. Other issues, like Palestine’s undefined borders and the fact that the Oslo Accords do not allow the PA to exercise criminal jurisdiction over Israelis, might also have to be resolved.

Then there is the issue of “complementarity”: the ICC can proceed against Israeli perpetrators only if it is demonstrated that the Israeli national justice system is “unwilling or unable genuinely” to prosecute the case. At one level, the failure of Israel’s justice system to credibly investigate war crimes against Palestinians is well documented. In 2010, for example, a UN committee of experts found that Israel had carried out no investigations to determine the identity of the senior officials who would have been most culpable for the commission of crimes during Israel’s 2008–09 “Cast Lead” assault on Gaza. But Israel is good at opening preliminary investigations to convey the false impression that it is willing to examine the conduct of its military. For example, Israel ostensibly opened 400 investigations after Cast Lead, but only three minor cases were eventually prosecuted (the harshest sentence was given to a soldier who stole a credit card). Such tactics could delay an ICC case for months or even years.

Finally, Israel is unlikely to cooperate with, and could easily disrupt, an ICC investigation. Because it directly or indirectly controls Palestine’s borders, Israel could decide to prevent evidence or witnesses from leaving the country for The Hague, where the ICC is headquartered. Moreover, Palestine could find itself having to hand over to the ICC its own nationals indicted for crimes such as rocket fire from Gaza into Israel, even as Israeli suspects avoid trial by refusing to surrender.

But perhaps most difficult are the political obstacles, chief among them the enormous pressure that Israel and its Western allies will almost certainly apply on the PA not to refer Israeli crimes to the ICC prosecutor, a necessary step before a case can proceed. Already in 2010, Israel’s Military Advocate General warned that the Israeli government would view PA pursuit of Israel through the ICC “as war.” Furthermore, Israel, the United States and the European Union have all threatened the PA with the withdrawal of financial aid and other retaliatory measures if it were to join the ICC. The day after Palestine submitted its application, Israel announced that it would withhold the next monthly transfer of Palestinian tax revenue it collects on behalf of the PA, totaling some $127 million. It has also threatened other unspecified “retaliatory steps.” While the United States has not formally stated its position, a law passed by Congress last month stipulates that if the Palestinians initiate any action against Israel at the ICC, the State Department would have to stop American aid to the PA, which comes to around $400 million annually. A senior State Department official has also warned that the PA’s ICC move will have implications for US aid to the PA.

It is true that there are other mechanisms for starting a case against Israel, ones that don’t rely on PA action. The prosecutor can open an investigation following a referral by another ICC member state or on her own initiative. But these avenues are also not immune from political interference. The ICC needs the support of powerful nations—especially the United States—to conduct its work effectively, which makes it directly vulnerable to pressure from those quarters no matter who brings a case. Israel and its Western allies could also pressure other ICC member states not to refer Israeli crimes to the Court. In any event, the prosecutor is unlikely to want to pursue a case against Israel without the support and cooperation of the PA.

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The real question therefore becomes: Does the PA have the political will to pursue a case against Israel, despite pressure from Israel and its Western allies not to do so? If past behavior is any indication, one must be skeptical: the PA has a track record of failing to use international legal mechanisms to achieve Palestinian objectives.

For example, in 2009, just after Cast Lead, the PA made an application to the ICC to investigate crimes committed during that assault. But a few months into the process the PA stopped cooperating with the prosecutor, apparently after it realized the negative consequences a case would have for its relationship with the West (the prosecutor eventually dismissed the case because Palestine had not yet achieved upgraded UN status). Later that year, the PA bowed to US and Israeli pressure and postponed a crucial vote on the Goldstone report at the UN Human Rights Council (the report, the result of a comprehensive UN investigation of crimes committed during Cast Lead, had recommended that Israel be referred to the ICC). The PA later reversed the decision as a result of popular Palestinian pressure, but then, in an attempt to appease Washington and other Western countries, it failed to insist that a General Assembly resolution endorsing the report include the necessary operational steps to ensure that its recommendations would be implemented.

This habit of forgoing legal action against Israel is no doubt due to the PA’s acceptance of a formula imposed by Israel and the West as part of the Oslo Peace Process, in which all Palestinian claims must be settled only through negotiation with Israel. Other measures that could be used to apply pressure—even nonviolent ones—are therefore deemed impermissible. In return for its obedience to this diplomatic straitjacket, the PA has secured the continued economic and political support of the West, upon which its survival depends.

Indeed, despite its application to the ICC, it’s not at all clear that the PA has decided to abandon this formula. Palestinian officials have said they are considering submitting a revised resolution to the Security Council in 2015, along the lines of the one just defeated; such a resolution would stipulate a further period of negotiations leading to an end to the Israeli occupation. If this is the case, the PA might be tempted to continue using the prospect of a case against Israel at the ICC as political leverage, rather than risk the diplomatic (and financial) fallout that legal action would provoke.

Whatever the PA decides to do, the ICC issue has taken on a wider significance in Palestinian society. It has come to symbolize a form of resistance against Israel outside the discredited “peace process”—a way to pursue Palestinian rights and make Israel accountable for its crimes. Polls have shown that a majority of Palestinians in the West Bank and Gaza were against the resumption of peace talks in 2013 and want the PA to take Israel to the ICC. Last summer’s assault on Gaza has only strengthened this sentiment. Even Hamas, which is at risk of prosecution for the rockets it fired from Gaza, has publicly urged the PA to pursue a case against Israel in the Court. Were the PA to do so, it would be adopting a strategy long advocated by Palestinian civil society: to use mechanisms of popular pressure—legal action, boycotts, protests—to advance Palestinian national aims rather than continuing to rely on endless negotiations. The question of an ICC case is therefore the ultimate test of whether the PA will follow the civil society approach of taking unilateral action to force Israel to end its occupation.