LI MIN/CHINA DAILY Following president-elect Joe Biden's statement that the United States would rejoin the 2015 Iran nuclear deal if Teheran returns to full compliance, China's Deputy Permanent Representative to the United Nations Geng Shuang told ambassadors at a Security Council briefing on nuclear nonproliferation on Tuesday that the other parties to the Iran deal should fulfill their commitments. And although the Teheran leadership, too, has said that it is ready to return to full compliance with the landmark nuclear deal as soon as the other parties honor their commitments, Iran is facing a precarious situation, particularly after the assassination of its leading nuclear scientist Mohsen Fakhrizadeh on Nov 27. Despite being forced to adopt an increasingly hard-line stance against Israel and the US, Iran cannot take any retaliatory action against Fakhrizadeh's killing, because that would make it even more difficult for Biden to lift the sanctions against Teheran and jumpstart diplomacy. Yet if Iran doesn't do anything to "avenge" Fakhrizadeh's death, its retaliation threats would sound hollow to not only other players in the region, especially its rivals, but also the Iranian people. Along with the assassination of Qassem Soleimani, the leader of Iran's elite military force and one of the most powerful leaders of the country in January, and an explosion that destroyed Iran's nuclear facilities in Natanz in July, the Iranian scientist's killing seems to have put Teheran in a spot. As such, the future of US-Iran relations, which nose-dived after the Donald Trump administration pulled the US out of the nuclear deal and launched its "maximum pressure" campaign, seems uncertain. Despite declaring that it would no longer abide by the nuclear deal's restrictions after the US pulled out of the pact, Teheran, of late, has reportedly reduced its involvement in Iraq and Syria in the hope that the incoming US administration will lift the sanctions. But the assassination of Fakhrizadeh has cast a shadow on the future of US-Iran ties, not least because Trump is still in office, and imposed sanctions on the Iranian envoy to Yemen on Dec 8. In retaliation, Iran blacklisted the US envoy in Yemen on Dec 9. Though no group has claimed responsibility for Fakhrizadeh's assassination, Iran claims Israel was behind it. Israel's intelligence agency Mossad has been involved in the killings of several Iranian scientists in the past decade, and Israel and the US jointly planned a cyberattack that damaged Iran's centrifuges through a computer worm called "Stuxnet" in 2010. Plus, Israeli Prime Minister Benjamin Netanyahu singled out Fakhrizadeh's name in 2018 from the Iranian documents that Israel had seized. Considering the close ties between the US and Israel, which have further deepened during Trump's presidency, if Israel had a hand in Fakhrizadeh's killing, the US likely knew about it in advance. So by accusing Israel of the killing, Iran is also pointing the finger at the US. The assassination is a political challenge for Iran, as it has exposed the loopholes in its intelligence and security, and prompted Iranian hardliners to demand that the government take reciprocal action, with some calling for a strike on the Israeli city of Haifa and ending cooperation with the International Atomic Energy Agency. Which has put President Hassan Rouhani's moderate government in a dilemma. But by targeting Israel or US facilities in the Middle East, Iran will only add fuel to the fire in the region, and worsen its already sour relations with the US, Israel and some other countries. Also, the moderates seem to be losing support among the Iranian public, as was evident in hardliners winning a majority of seats in the parliamentary election in February－raising fears that a hardliner could win the Iranian presidential election in June next year. Resolving the Iranian nuclear issue is an extremely difficult task. The Trump administration's maximum pressure dashed Iran's hope of being free of international sanctions in return for pledging to not develop any nuclear weapons. To press the other five signatories to the nuclear deal (the four other permanent UN Security Council members plus Germany) to fulfill their requirements, Iran has been gradually reducing compliance with the pact. For example, in July 2019, Iran announced the breaking of the 300-kilogram limit for enriched uranium stock and the 3.67 percent limit for uranium enrichment. On Nov 5 last year, it announced the activation of the centrifuges at the Fordow facility. And on Jan 5 this year, it announced that it would no longer honor the nuclear deal's terms. Besides, the nuclear scientist's killing could prompt Iran to further intensify its nuclear program, jeopardizing the chances of any talks on the full revival of the nuclear deal. And Fakhrizadeh's killing, despite being a great loss for Iran, is not likely to slow down Iran's nuclear program, because after decades of efforts, it has developed the technology and talents to take it forward. In fact, two days after Fakhrizadeh's death, the Iranian parliament passed a bill, "Strategic Action to Lift Sanctions", aimed at enriching uranium to 20 percent and above. If Iran succeeds in doing so, it would be the most serious breach of the nuclear deal. It seems foreign attacks on its leading figures, including top scientists, have made Iran more determined to make the nuclear program a success. Another challenge for Iran is the deteriorating external environment. Still, many expect Iran to exercise restraint until Jan 20, when Biden is scheduled to take oath of office as US president. Perhaps Middle East countries opposed to Iran are using the last days of Trump's presidency to launch a barrage of attacks against Iran to force it to retaliate and thus jeopardize the chances of resolving the disputes with the US through peaceful dialogue. The killing of Fakhrizadeh could be part of that ploy. Israel and some other Middle East countries, including Saudi Arabia, have joined hands to contain Iran. And since Iran is likely to respond to such moves in some form, even if it doesn't resort to attacks, the power games in the region will intensify, causing the already high tensions to rise further. If Iran's strategic tolerance gives way to desperation, and it launches revenge attacks, the Middle East will become even more turbulent. But if it continues to exercise restraint, the period from January, when Biden assumes office, to June, when Iran holds presidential election, could provide Teheran and Washington the opportunity to hold negotiations to settle their disputes, leading to the revival of the Iran nuclear deal. Wang Lei is an assistant research fellow at the Institute of World Economics and Politics, Chinese Academy of Social Sciences. The views don't necessarily reflect those of China Daily. If you have a specific expertise and would like to contribute to China Daily, please contact us at firstname.lastname@example.org, and email@example.com.