For most Palestinians, the prisoner swap deal between Israel and Hamas is a cause for celebration. For President Mahmoud Abbas, it’s shaping up as political blow and a security headache.

Israel and Hamas announced the deal today after weeks of secret negotiations mediated by Egyptian and German representatives. It calls for Israel to free about 1,000 Palestinians in exchange for the release of Cpl. Gilad Shalit, held by Hamas since 2006. Previous exchanges have been hugely popular among Palestinians, who in opinion polls regularly cite the imprisonment of their loved ones by Israel as one of their biggest sources of anxiety.

The problem for Abbas is that he and his Fatah party had no role in the agreement. In fact, it was engineered by his main rival, Hamas political chief Khaled Meshaal, whose announcement about the deal was carried live on Palestinian state-run television. Hamas and Fatah have been on bad terms since they fought a brief civil war over Gaza in 2007. Since the list of prisoners due to go home includes Palestinians from across political and geographic divides—West Bankers and Gazans, members of Hamas and Fatah—Meshaal could legitimately present it as something tangible his party achieved for all Palestinians. “The deal represents the unity of our nation because it includes representatives of all the factions,” he said in his address.

Abbas, by contrast, has had no tangible achievement to show for his leadership in some time. His effort to reconcile with Hamas earlier this year and schedule new elections—something Palestinian protesters had been demanding—has largely collapsed. In New York, Abbas’s request last month for Palestinian membership with the United Nations did not have the diplomatic punch some had expected, and has so far cost the Palestinian Authority $200 million in American financial assistance. At the very moment Meshaal was announcing the prisoner agreement, Abbas was touring Latin America asking foreign leaders for their support in the membership bid—a campaign that, with America’s veto power in the U.N. Security Council, has no chance of succeeding.

Then there’s the matter of the prisoners, many of them hardcore Hamas militants. According to Meshaal, more than 300 of those slated for release have been serving life terms for organizing bombings and other attacks on Israel. While some number of them will be sent to Hamas-controlled Gaza or deported overseas under the agreement, many will end up in the West Bank, where they’ll become Abbas’s problem. With the rivalry between Hamas and Fatah surging in the West Bank, the insertion of more Hamas militants into the area could have at least some effect on the balance of power. It’s unlikely to topple Abbas, but it might force him to act more aggressively against the group than is politically advantageous. Should the Hamas men resume their plotting against Israel, Prime Minister Benjamin Netanyahu will hold Abbas and his security agencies responsible. Either way, it’s a lose-lose for the Palestinian president.

Some of the damage might have been mitigated had Marwan Barghouti been included in the swap. A member of Abbas’s Fatah party, Barghouti enjoys broad popularity in the West Bank and Gaza. His release, even in the context of a Hamas-negotiated agreement, would have galvanized Fatah and boosted Abbas. Instead, his ongoing imprisonment signals to Palestinians that Hamas’s strategy—capturing soldiers and holding them as bargaining chips—works better than diplomacy. For Abbas, and for Israel as well, it’s a dangerous message.