Hussein Agha and Ahmad Samih Khalidi have been involved in Palestinian peace negotiations for three decades, and are senior associate members of St. Antony’s College, Oxford, and co-authors of “A Framework for a Palestinian National Security Doctrine.” Agha most recently carried out backchannel negotiations during the Obama Administration’s failed effort to broker an Israeli-Palestinian peace agreement.

As President Trump prepares for yet another attempt to resolve the Palestinian-Israeli conflict, the ground is shifting under his feet. While Israel’s willingness to offer an acceptable deal is increasingly open to question, with nothing to suggest that its terms are likely to soften with time, the Palestinians are sliding toward the unknown. With the slow but sure decay of the Palestinian political scene, the President of the Palestinian Authority, Mahmoud Abbas (Abu Mazen), represents the last slender chance for a negotiated settlement: he is the sole remaining national leader of his people with sufficient, if dwindling, authority to sign and ratify a deal. For President Trump and his team, as well as for all those seeking to end this century-plus-old conflict, there should be no doubt about the moment’s urgency. After Abbas, there will be no other truly weighty representative and legitimate Palestinian leadership, and no coherent national movement to sustain it for a long time to come.

Over six days in late November and early December, 2016, Fatah, the Palestinian national liberation movement, convened its seventh congress in Ramallah, the de-facto capital of the Palestinian Authority. Despite the lengthy speeches and festive air, the conference did little to dispel what had become unmistakable: the slow expiry of a once vibrant movement. Long on show and short on substance, the meeting hardly touched on any of the mounting political challenges facing the Palestinian people. The Congress was no more than a confirmation of the current order and a reaffirmation of its total and unprecedented control over Fatah, the P.A., and its ostensible parent, the Palestine Liberation Organization.

The contemporary Palestinian national movement—founded and led by Yasser Arafat and embodied by the P.A., Fatah, and the P.L.O. over the past half century—is reaching its end. As its institutions wither and its leaders fade away, there is no obvious successor to take its place.

Looking back, the 1993 Oslo Accords marked the Palestinian national movement’s highest political accomplishment and the beginning of its slow decline. From then onward, the P.A. has been trapped between its original revolutionary mission as an agent for liberation and its new responsibilities as a proto-state, with its attendant civil, bureaucratic, and security establishments.

For a while, with its historic resistance leader at the helm, the national movement sought to reconcile its contradictory missions. But, with Arafat’s death, Fatah lost not only the forefather and leader of its foundational militant phase but its very raison d’être. Without “armed struggle,” the national movement had no clear ideology, no specific discourse, no distinctive experience or character. In the absence of a genuine and independent state, it was unable to transform itself into a ruling party, as, for example, the African National Congress did, in South Africa. It remained incomplete and suspended: a liberation movement not doing much liberating, locked in a fruitless negotiating process, and denied the means of government by a combination of Israeli obduracy and its own inadequacies.

With the passing of Arafat and most of his colleagues, Fatah’s ability to hold its fractured parts together waned. The social and political milieu of the West Bank and Gaza—steeped in clannish and personal influences—highlighted local fiefdoms and deep-rooted tensions. Severed from its history in the lands of exile, and without a rationale to supersede its original liberationist impulse, Fatah became mired in narrow and parochial turf wars. This was, in turn, compounded by its leaders’ failure to attract new blood. Unlike the experience of exile that formed a unifying Palestinian bond, that of the territories never managed to produce viable leaders who could forge a truly national enterprise out of highly localized components. The powerful pull of local ties made it almost impossible for a Hebronite to have a genuine popular base in Ramallah, or for a Gazan to have a credible say in the West Bank.

With no new leaders, no convincing evidence of validation, no marked success in government, no progress toward peace, fragile links to its original setting abroad, and a local environment buffeted by the crosswinds of petty quarrels and regional antagonisms, Fatah fundamentally disappeared as a real political agent.

The national movement was built on representation, activism, and achievement. It faithfully and energetically represented the broadest spectrum of Palestinian national sentiment, from the most visceral to the most rational, and it re-created the forgotten Palestinians as central players in their own drama and as a cause worthy of recognition across the world—epitomized by Arafat’s address to the U.N. General Assembly in 1974.

Today, none of these elements of success are evident. The all-encompassing P.L.O. has lost its representative status; the aging factions that still sit in its councils have little, if any, extensions inside or outside Palestine. The spirit of activism and dynamism has moved outside P.L.O. structures and onto the streets with no clear organization or political direction. And the P.A./P.L.O.’s achievements have been largely formalistic if not fake—a more advanced status as “observer state” at the U.N., but with no tangible improvement to the situation on the ground.

Arafat’s management was an integral element of the dynamism of the Palestinian national movement, and the transition from Arafat to Abbas passed smoothly because it was recognized as a continuation of the founding days of the national movement. Abbas may have needed formal elections to consolidate his position and gain acceptance in the international community, but, without his previous revolutionary credentials and association with Arafat, Abbas’s legitimacy would have been questioned from the start.

Abbas did not want, and could never occupy, Arafat’s place. His standing with his own people was deeply damaged by his persistent and infertile engagement with the peace process, his unwavering opposition to forceful struggle, and his fulsome dedication to security coöperation with Israel. As his tenure extended beyond his initial electoral mandate, the Palestinian political system developed many of the characteristics of a one-man Presidential regime, but without the élan of a popular leader. Later years witnessed a growing tendency toward unmitigated centralization, rule by decree, and the concentration of power. Other instruments of government were muted, and a determined effort was made to control what remains of Fatah’s decaying structures and to silence genuine political dissent. What used to be a vibrant if fractious political debate, nourished, tolerated, and often exploited by the leadership, has turned into a dull and dismal discourse, steered by political directives, and driven by fear of suppression and the loss of position inside an ever-swelling bureaucracy. A distinction between “President” and “leader” has emerged, and not necessarily in a manner that serves either.

Abbas’s years as President have not been without their share of achievements. His peace policy provided the P.A. with a formidable firewall against the kind of international pressure associated with the Palestinian national movement’s past violence, and added to a growing sense of unease at Israel’s occupation. For some, this by itself is a major national achievement. The P.A. has been sustained as a would-be state, and, since 1994, many of the day-to-day governing affairs of municipal, health, education, and other functions have been in Palestinian hands for the first time.

Abbas’s dedication to negotiations, diplomacy, and non-violence has shifted the burden onto the other side. While the current Israeli leadership’s peace credentials are widely disputed, Abbas’s international image as a man of peace remains largely intact. At the same time, he has managed to hold on to the historical and fundamental Palestinian demands; he has not wavered from the P.L.O.’s goals for a state along the 1967 borders, with its capital in East Jerusalem, and a just resolution to the refugee problem. He put an end to the chaos of the second intifada. He has continued engaging with a broad range of Israeli opinions, and has assiduously sought to cultivate what remains of the Israeli peace camp and to engage with Jewish leaders and communities abroad. Perhaps most important, he has succeeded in insulating the Palestinian people from much of the violence and destruction of the “Arab Spring” and from the growth of Salafi and jihadist movements in the West Bank.

All in all, Abbas’s era has enhanced the Palestinians’ moral standing and lent traction to their cause and narrative. But these achievements are in danger of being overshadowed by new circumstances and challenges. Abbas may have helped to underpin the legitimacy of the Palestinian cause, particularly in the West, but his approach has failed to demonstrate sufficient payoff in peace negotiations, changing the unacceptable status quo, or in attracting popular support to revive the movement’s declining fortunes. The thirteen years of his rule have produced no significant change in Israel’s stance; in fact, Israel’s terms for a final-status resolution on such issues as Jerusalem, security, and the extent of Palestinian sovereignty have notably hardened.

Furthermore, the Palestinians’ readiness to take the negotiating path to its logical conclusions was restrained by a perception that they were winning the moral and psychological high ground. The paradoxical effect was to make it harder to progress toward an agreement with Israel because it seemed that other influential parties might do the job.

The past decade has also witnessed a series of seemingly inconsistent and not well thought-out Palestinian diplomatic moves, including the welcoming of, and then backtracking on, the Goldstone Report, in 2011; on the 2008 Gaza war; the unconvincing threats by senior Palestinian officials to dismantle the P.A.; the overselling of the bid to create international facts by joining various U.N. bodies; the pursuit of desperate and futile initiatives such as the proposals, in 2016, by the former French President François Hollande for an international conference; and the failure to make diplomatic progress even in the shadow of a relatively friendly U.S. Administration. As a result, the entire notion of peace negotiations has been discredited and consigned to outright condemnation, deep disbelief, and profound apathy among Palestinians, further weakening the national movement’s political credibility and standing.

The growing public criticism of security coöperation might best encapsulate the P.A.’s dilemma. Security coöperation is meant to serve the national interest by preventing armed activities that threaten to elicit a disproportionate Israeli response. Yet coöperation ends up serving Israel by sustaining the occupation’s low cost and helping to perpetuate it. The primary function of any authority is to provide security to the people it represents. P.A. security forces can do very little to defend their own people both in the territories and abroad, where at least half of the estimated total of twelve million Palestinians reside, in the face of third-party threats, individual Israeli assaults, settler violence, or the organized actions of the Israel Defense Forces. Palestinians are consequently left vulnerable to overwhelming Israeli power and the hardening fist of their own security forces at the same time. Insofar as security coöperation is seen as an auxiliary function to the occupation, it has added to a sense of helplessness and loss of agency and has focussed popular anger and frustration away from the struggle for freedom and independence. Whether the Palestinians would be better served in raw contact with the occupation without the mediating influence of the P.A. is open to question, but the cumulative corrosive impact of the P.A.’s role as shield and security subcontractor to the occupation is undeniable—especially with no accompanying political returns.

The Palestinian loss of faith in a negotiated settlement reflects a loss of faith in the agencies that have sought to pursue it. To the extent that Fatah, the P.A., and the P.L.O. have been dedicated to a two-state solution, their failures—from liberation to governance to peacemaking—have lessened public support for the desirability or viability of the goal itself. Besides the bloated P.A. bureaucracy, almost all sectors of the Palestinian people have been alienated from the methods and practices of their representative bodies, and have largely lost any real sense of investment in their diplomacy. What was once seen as a national unifying program is now viewed with deep skepticism and indifference.

Of course, not all change has come from within. There is no doubt that the regional and international environment has shifted in unfavorable ways. A “Third World” moment—in which the Palestinian national struggle found a natural home within the liberationist and anti-colonial movements of Algeria and Vietnam, and was embraced by emerging Asian powers as part of their new sense of independence—no longer exists. The recent era has seen a move in the opposite direction; there may be greater understanding for the Palestinian cause in the West, but many of the Palestinians’ former Third World allies have chosen economic self-interest in place of ideological commitment. India’s wavering support for the Palestinians at the U.N. and China’s growing trade and military ties with Israel are examples.

The Arab environment has also clearly changed. Fatah was originally as much an assertion of Palestinian “independence of will” in the face of Arab hegemony as it was a revolt against Israel’s plunder of the homeland. Despite many political conflicts and bloody confrontations with numerous Arab states such as Jordan, Syria, and Lebanon, the P.L.O. continued to draw political and financial support from its hinterland, from the Gulf States, and from a popular base that was deeply sympathetic to the Palestinian struggle. Fatah and the P.L.O. may have been largely dependent on Arab aid, but the multiplicity of sources and the constant rivalries among the Arabs themselves accorded the movement a wide margin of freedom. If one source of funding and support was severed, another was more than likely to appear. And, despite a high degree of financial dependency, the movement maintained political freedom of action: the P.L.O.’s dramatic support for a two-state solution in 1988 and the 1993 Oslo Accords were “independent” Palestinian decisions made without wider Arab consent, regardless of their wisdom at the time or since.

In the regional turmoil and violence of recent years, the Palestinians largely lost the skill of maneuvering among the Arab parties and their conflicting interests, and have become more dependent on other external support. As Arab financial aid shrinks, a new bloc of Arab states, comprising Egypt, Jordan, Saudi Arabia, and the United Arab Emirates, has a growing hold over the Arabs’ say on Palestine, further narrowing P.L.O. independence. Equally, the P.A. has become more and more reliant on the flow of funds from the U.S. and the European Union, and on Israel’s good will in dealing with the daily needs of the Palestinian population in the territories. Once a useful tool for maximizing freedom of action, multiple sources of outside support are now a means of leverage to further constrain Palestinian decision-making.

The post-Abbas era will launch an uncharted and unpredictable course. The founding fathers’ historical legacy and imprint of legitimacy is disappearing. The Palestinian refugees and the broader community in exile have no real agency, means of expression, or instruments to reflect their will. Fatah’s ongoing conflict with Hamas, the unrest in Gaza and the West Bank, and the institutional failures of the P.A. all point to an increasingly narrow and more tenuous form of leadership, one that is based more on formal elections, and, consequently and paradoxically, on less solid and genuinely representative grounds.

A leader elected on and by the West Bank, without continuity with the fading national movement, may not be openly rejected by the fractured components of the Palestinian people, but will, in the best of circumstances, have only limited national appeal and authority. Unlike a leader chosen by widespread acclaim, a narrowly elected leader, or one selected as a compromise among the different factions, cannot claim to represent those who lie outside his or her constituency, or to speak on their behalf. It is doubtful that such a leader will be able to rely on majority support or rally it, if and when decisions of national import are at stake. Abbas’s power derives from the fact that those who may otherwise criticize or reject a deal will abide by his terms. His signature not only imparts legitimacy to an agreement but absolves opponents from any responsibility for the concessions it may entail. Despite his limitations, Abbas may be the last Palestinian leader with the moral authority and political legitimacy to speak and act on behalf of the entire nation on vital existential issues such as a final agreement with Israel.

If the incoming Palestinian leadership is likely to be less representative than its predecessors, the degree to which it has a mandate to conclude and sustain a future agreement with Israel may be open to question. This will necessarily affect Israel’s own willingness to agree to a deal—already evident in Prime Minister Benjamin Netanyahu’s repeated insistence that Israel will “never” cede security control over the West Bank. It will also affect the role and posture of third parties, such as the U.S., in facilitating or pushing for a deal, and its possible content will be less likely to approximate Palestinian terms for a settlement. The recent spate of well-attended popular meetings hosted by Turkey, Egypt, Iran, and even France and Holland may inaugurate a new phase in which the P.L.O. faces growing pressure to defend its credentials as the “sole and legitimate representative” of the Palestinian people, with further limitations on its margin of maneuvers at home and abroad.

Twenty-four years after Oslo, the security establishment is perhaps the most enduring and powerful institution spawned by the P.A. Nourished and fortified by Israel, the U.S., and major European and Arab parties as part of the post-second-intifada reform process and designed to control violence and internal dissent, P.A. security forces have become the most efficient, visible, and functional arm of Palestinian governance. In the absence of countervailing legal and political institutions, organized popular movements, or capable representative bodies, there will be a strong temptation for the security forces to fill the vacuum of a frail national leadership, if only to avoid a comprehensive institutional collapse.