The newly established state of Israel captured West Jerusalem in the aftermath of the 1948 War and East Jerusalem in the 1967 War; however, neither military acquisition was recognized internationally. In 1995, though, the US Congress adopted the Jerusalem Embassy Act claiming Jerusalem as the eternal capital of Israel and that it should not be divided. However, each US administration since then, both Democrat and Republican, has stalled the implementation of this act, citing national security interests.
President Trump would be similarly well-advised not to act on his pledge to move the embassy to Jerusalem, for the following reasons.
First, the Trump administration would be contradicting America’s longstanding policy of considering Jerusalem an occupied city as part of the 1947 UN Partition resolution to internationalize the city and keep it open for all three heavenly religions.
Second, it would contradict US commitment to the 1993 Oslo Accords in which Jerusalem remains one of five major issues to be settled in the final peace negotiations between Israelis and Palestinians. A US recognition of Jerusalem as Israel’s undivided capital would undermine this commitment and diminish Israeli motivation to settle this issue peacefully while giving Muslim radicals the pretext to escalate terrorist tactics against civilians in Jerusalem.
Third, the move would widen the gap between the US and its European allies. Following the Mideast peace conference in Paris, EU foreign affairs chief Federica Mogherini expressed her worry that moving the US embassy to Jerusalem would have "serious consequences" and advised the Trump administration against moving the US embassy to Jerusalem as she "worried about a possible worldwide popular backlash.” Mogherini affirmed the European Union delegation will keep its embassy in Tel Aviv and continue to respect UN resolutions opposing Israel's annexation of east Jerusalem, which the Palestinians want as the capital of a future state. Mogherini said at a press conference that she believes “it is very important for us all to refrain from unilateral actions, especially those that have serious consequences in large sectors of public opinion in large parts of the world." She added: "I'm worried that large parts of public opinion in parts of the world that are quite significant -- the Arab world but also Africa, Asia and parts of Europe -- could have in reaction of a move that for sure would not be in line with the international consensus." The move would also alienate the US in the broader international community since it is not in line with the international consensus embodied in UN Security Council resolution 478 of 1980 which opposed Israel's annexation of east Jerusalem as part of its ‘unified capital’.
Fourth, the move would weaken support from the American-allied regimes in the Arab world such as Jordan, Saudi Arabia, Morocco, and Egypt which the US needs as allies in its war against terrorism and the Islamic State.
Fifth, the move could cause tumult in the Arab streets, damaging Israel’s timid cooperation with moderate Arab states. If the stalled peace process were to ignite into violence it very well might target US citizens and interests in the region, further isolating the United States in the Arab and Muslim world. Relocating the American embassy from Tel Aviv to Jerusalem, as King Abdullah of Jordan asserted to Trump in his recent visit to Washington, “would threaten the two-state solution and have a detrimental effect on the Israeli-Palestinian conflict.”
Sixth, the step would have deep religious overtones in both the Muslim and Christian world. In the Muslim world, it will be perceived by the masses as part of the war launched by the Trump administration against Islam, driving many to support the ideology of the Islamic State. Instead of “eradicating radical Islamic terror from the face of the Earth,” as Trump pledged in his inaugural address, it would empower it. In the Christian world, the move would be perceived as conceding Jerusalem to Judaism only. This would signal a disregard for Christian religious rights and sites in the holy city of Jerusalem.
In sum, such a move would inflame the region unnecessarily, exposing US interests and Americans to attack while causing political instability for moderate Arab regimes. There are not many benefits for the United States - and even for Israel - to take such a risky move. Trump, as a shrewd businessman, would do well to carefully weigh this decision and act accordingly.