當地時間2018年1月12日，美國總統特朗普宣布，美國仍將遵守《伊核問題全面協議》，暫時不會恢復此前因為核計劃而對伊朗實施的制裁。但特朗普同時發出“最後通牒式”警告，稱必須要對伊核協議進行修改，否則這將是他給予的最後一次延長制裁伊朗的豁免期，屆時美國將退出協議沒商量。這一表態雖暫時緩解了人們對美國單方面退出伊核協議的擔憂，但伊核協議的命運仍前景不明，三個月的時間窗口之後是被美國單方面撕毀還是經修改得以繼續存續，擬或排除美國而由其他簽約方按照原有協議內容繼續執行下去，仍不得而知。

一方面，特朗普的態度很堅決，要求對他所稱的美國歷史上籤訂的“最糟糕的協議”進行修改。據了解，其希望修改的主要內容是，永久限制伊朗鈾濃縮活動、限制伊朗發展彈道導彈項目和伊朗在中東的軍事動作等均納入核談判。另一方面，伊朗的態度同樣堅決。伊朗外交部已發表聲明強調，伊朗現在不會接受、未來也不會接受任何就伊核協議的修改，伊朗也不會實施超出這份協議之外的任何舉措。聲明還強調美國必須像其他國家一樣全面履行其承諾，假如美國以各種荒謬的借口不履行這些承諾，美國將承擔相關一切後果。

伊朗態度的堅決主要基於兩個方面。首先是伊朗很好地履行了伊核協議規定的義務。自2015年7月伊核協議簽署以來，國際原子能機構的歷次報告也都認可了這一點，即便特朗普政府在向美國國會報告時，似乎也很難從伊朗執行協議的過程里挑出什麼瑕疵。其次，伊核協議是一項國際多邊協議，是由包括美國、俄羅斯、中國、德國、法國、英國在內的六方與伊朗經過艱難談判達成並由安理會認可通過的多邊國際協議。目前，除了美國一方提出修改協議並威脅“退群”以外，其他簽約各方均支持伊朗的主張并力挺協議的繼續實施。

特朗普態度的堅決也主要基於兩個方面。一是兌現其競選承諾。從參與競選到就任總統以來，特朗普一直對伊核協議表達強烈不滿，稱協議對美國而言是災難性的，並始終威脅要退出協議。伊核協議是奧巴馬的“外交遺產”，特朗普上台後推出的各項政策實際上都是在對奧巴馬的“遺產”進行否定式“清零”，如修改醫改法案、退出TPP、退出《巴黎協議》等等。二是，特朗普政府毫不掩飾地把伊朗作為美國中東戰略的主要對手和敵人。特朗普總統執政以來不斷加大和加強與以色列和沙特的戰略盟友關係，把以、沙兩國視為美國中東戰略倚靠的重要盟友和支柱。而以色列和沙特不僅一直是伊朗的戰略競爭對手，而且都對奧巴馬政府簽署的伊核協議不滿，希望修改並撕毀該協議。

事實上，伊核協議目前最需要的是保護和繼續推進，而絕不是退出和撕毀。協議的撕毀不僅對當事國伊朗不利，而且對美國及其中東盟友以色列和沙特同樣不利，對國際核不擴散努力也是一個沉重打擊，其最終結果只會是負面和多輸。對伊朗而言，協議的撕毀將激發國內保守派的新一輪反美浪潮，並可能迅速啟動其報復性的鈾濃縮等核能研發進程，並阻斷其剛剛開啟不久的與世界接軌和開放的大門，加劇伊朗與西方的對抗。對以色列和沙特而言，伊朗核能研發的重啟自然增強了兩國的戰略疑慮和不安全感，同時也會刺激兩國同步進行核能研發，從而導致中東地區的新一輪軍備競賽和不穩定。對美國而言，單方面撕毀多邊國際協議不僅會失信於天下，嚴重損害美國的國際信譽、國際形象和“軟實力”，而且不利於美國參與談判解決類似朝核問題的其他國際熱點問題。最後，對國際和平與安全而言，伊核協議這一歷史性協議的達成不僅是有關各方長期艱苦談判的結果，是符合各方利益的多贏協議，它更是多邊主義、和平主義和理性主義的勝利，是外交智慧、國際合作以及用和平談判手段解決棘手的核問題的成功先例。這樣成功且來之不易的國際合作成果，更需要有關各方精心呵護，使其走的更穩和更遠，為世界面臨的其他類似問題發揮示範和表率作用，而不是釜底抽薪，以單方面不負責任的撕毀協議讓多年國際合作和努力化為灰燼。

目前，除美國以外的其他五個伊核協議簽署國均表示要繼續維護和執行協議。至於美國提出的有關伊朗發展彈道導彈項目等問題，因其與伊核問題無關，因此不需要摻雜到伊核協議裡面來談，使原有問題複雜化，而是應該在協議以外的其他機制里來談判解決。

On 12 January 2018, President Donald Trump announced that the US would still honor the terms of the Joint Comprehensive Plan of Action with Iran and waived sanctions one more time. But he also issued an 'ultimatum': the agreement must be revised or US will withdraw from it. The future of that deal remains uncertain. Will it be scrapped by the US after three months or be retained with revisions? Or will the other signatories of the deal follow its original terms?

On the one hand, Trump's attitude is quite firm in demanding revision of what he described as the 'worst' accord in American history. The revisions he wants reportedly include permanent restrictions on Iran's nuclear enrichment activities, restrictions on its ballistic missile program, and inclusion of its military operations in the Middle East in the nuclear negotiations. On the other hand, Iran also has a firm attitude. The Iranian Foreign Ministry has already issued a statement, stressing that Iran does not and will not accept any revision to the agreement and that Iran will not implement any measures outside of the agreement. It also stressed that the US must fully uphold its commitment like other parties to the agreement and bear all the consequences if it fails to do so under any absurd excuse.

There are two reasons behind Iran's firm attitude. First, Iran has met its obligations under the nuclear agreement, which has been supported by IAEA reports. Even the Trump administration, reporting to Congress, has found it hard to find flaws in Iran's implementation. Second, the Iranian nuclear deal involves a multilateral agreement concluded through tough negotiations between Iran and the US, Russia, China, Germany, France, and UK and endorsed by the UN Security Council. At present, only the US has proposed modifying it and threatened to withdraw, while all other parties support Iran's desire to continue implementing the agreement.

There are also two reasons behind Trump's firm attitude. The first is his campaign promise. Since the beginning of his campaign, Trump has complained about the Iranian nuclear deal, describing it as disastrous to the US and threatening to withdraw. The agreement is President Barack Obama's diplomatic legacy. Since taking office, President Trump has introduced various policies to negate Obama's legacies, including the Obamacare reforms, and withdrawal from the TPP and Paris Climate Agreement. Second, the Trump administration makes no secret that America regards Iran as its main adversary in the Middle East. President Trump has consistently increased and strengthened strategic ties with Israel and Saudi Arabia, its two important allies in the region. These two countries are Iran's strategic competitors and have expressed unhappiness over the deal with Iran and hope to revise or scrap it.

As a matter of fact, what the agreement needs most now is protection and continued implementation. Withdrawal which will hurt not only Iran but the US and its Middle East partners, i.e., Saudi Arabia and Israel, and deal a heavy blow to the international nuclear non-proliferation regime. In Iran, scrapping the agreement will stimulate another wave of anti-Americanism among the conservatives which may well lead to prompt reactivation of uranium enrichment and other nuclear R&D activities, interruption of its nascent effort to open to the outside world and increased confrontation with the West. For Israel and Saudi Arabia, Iran restarting nuclear energy research will increase their strategic misgivings and sense of insecurity and stimulate them to do the same, thus triggering a new arms race and increasing instability in the Middle East. For the US, unilaterally scrapping a multilateral agreement will seriously undermine America's international reputation and soft power, thus harming US participation in the negotiated solutions of other similar international issues. For international peace and security, the historic nuclear agreement was the result of a long, arduous negotiation between the relevant parties. It was a win-win deal serving all parties' interests. It was a victory of multilateralism, pacifism, and rationalism and a successful precedent for resolving tough nuclear issues through international cooperation and negotiation. Irresponsible unilateral scrapping of the agreement will turn years of international cooperation into dust and ashes.

At present, all five other powers involved in the agreement have stated their willingness to continue honoring the Iranian nuclear agreement. The question of Iran developing a ballistic missile program, which was raised by the US, has nothing to do with the nuclear issue and should not be brought in to complicate the situation. It should instead be addressed through negotiations in external mechanisms.