Former U.N. Ambassador John Bolton began his tenure as National Security Adviser on Monday, taking over the position from H.R. McMaster. To say that Bolton has a full plate as he sits down at his desk would be an understatement.

Here are the seven most urgent national security crises he faces on Day One.

Syrian chemical weapons attack: The headlines on Bolton’s first day are dominated by the latest chemical weapons attack in Syria, followed by a retaliatory strike on a Syrian airbase that remained enigmatic on Monday morning. (Russia and Syria claim it was an Israeli strike on an airfield in Homs province that is used by Iranian forces and allied Syrian militia).

“The brutal chemical weapons attack in Syria presents Bolton with an immediate crisis that will highlight the biggest questions surrounding his appointment, offering an early examination of how his vision of the robust use of U.S. power abroad will ally with Trump’s own hawkish instincts,” CNN judged on Monday, arguing that the situation is a nightmare scenario for any national security adviser because the options to respond to such a horrific violation of the global prohibition against weapons of mass destruction are so limited.

One of Bolton’s first acts as NSA was attending an emergency session of the White House National Security Council on Syria.

In February, during one of his frequent appearances on Breitbart News Daily, Bolton approved of Israeli action against Iranian assets in Syria and said the Trump administration “has a lot of ground to make up” in re-establishing American influence in the region.

“Under Barack Obama, we essentially walked away from it, basically as part of the Iran deal. The Iranians wanted a less visible, palpable American presence, and Obama was happy to give it to them like he would give them essentially everything else to get that nuclear deal,” Bolton said.

Bolton has criticized President Obama for failing to stick to his “red line” against chemical weapons in Syria, and emphasized the importance of teaching Syrian dictator Bashar Assad that he cannot use such weapons with impunity.

Weapons of mass destruction have long been one of Bolton’s top concerns. As Undersecretary of State during the George W. Bush administration, Bolton led the creation of the Proliferation Security Initiative, a classic example of the “coalition of the willing” concept in which select European powers worked with the United States to efficiently interdict shipments of WMD components. The PSI was seen as successful enough to continue through the Obama administration.

Tensions with Russia: Bolton commences his duties as National Security Adviser just a few days after the Trump administration announced a new round of sanctions against Russian entities and individuals, including government officials.

On Monday, Russian Prime Minister Dmitry Medvedev denounced the sanctions as “illegitimate” and ordered his government to prepare retaliatory actions against the U.S. government. The Russian government also said it would support companies hit by U.S. sanctions after the Russian stock market plunged on Monday.

Tensions with Russia can be expected to escalate over the WMD crisis in Syria. President Donald Trump personally blamed Russian President Vladimir Putin for allowing “Animal Assad” to perpetrate a “mindless chemical attack” in a tweet on Sunday morning. Later that day, the Russian Foreign Ministry warned that a U.S. military response to the chemical attack would be “unacceptable” and would result in the “most serious consequences.”

Russia is fighting an increasingly bitter feud with the United States and the United Kingdom over the attempted assassination of former spy Sergei Skripal and his daughter with nerve agents. The U.K. is working with European powers to forge a consensus that Russia become an intolerable threat to international security.

The new U.S. National Security Adviser is receptive to that argument.

“It’s an act of defiance. It’s saying to London and the other western capitals, ‘what are you gonna do about it?’ Well, I think there should be a very strong answer to that,” Bolton said of the Skripal poisoning in March.

North Korea: Bolton arrives in office less than 24 hours after U.S. officials confirmed that North Korean dictator Kim Jong-un has indicated he is prepared to discuss denuclearization when he meets with President Trump. The details of the prospective meeting have not yet been finalized, but it should theoretically occur within the next few months.

Bolton is deeply skeptical of North Korea’s appetite for negotiations. He views Pyongyang as an almost unparalleled nuclear proliferation threat, as well as a key source of chemical weapons supplies for noxious regimes like Syria.

“That’s what North Korea does. It sells anything to anybody for hard currency. Just as it sells chemical weapons, just as it was financed—probably by Iran—to build a nuclear reactor in Syria destroyed by Israel in 2007, the day it gets deliverable nuclear weapons the bazaar will be open, and the highest bidders will be welcome,” he told Breitbart News Daily in March.

Bolton tends to view North Korean offers of negotiation as delaying tactics, running out the clock as Pyongyang scrambles to perfect nuclear missile technology. He has often stated that North Korea’s nuclear threat can only be decisively ended by reunifying the Korean peninsula under a U.S.-aligned democratic government in Seoul.

Bolton has suggested U.S. policy should be focused on getting China to accept that outcome as the only long-term solution to its own security interests, while the U.S. and its allies strive to weaken the Kim regime and hasten reunification. A Trump-Kim deal that achieves anything less than total, immediate, verifiable denuclearization by North Korea would likely be viewed with deep skepticism by the national security adviser.

Iran nuclear deal: Iran is North Korea’s only real competitor for the position of top nuclear proliferation threat in Bolton’s view. In fact, he has portrayed North Korea and Iran as two faces of the same menace, citing their history of cooperation on missile and nuclear technology. “Whatever capability North Korea has, Iran will have the next day,” he warns.

Tehran has lately been threatening the United States with dire consequences if Trump withdraws from the deal.

“Iran will not violate the nuclear deal, but if the United States withdraws from the deal, they will surely regret it. Our response will be stronger than what they imagine and they would see that within a week,” Iranian President Hassan Rouhani said on Monday.

Bolton sees the Iranian government as a brutal tyranny that frequently resorts to using violence against its own people, a malign influence on the Middle East, and a dangerous supporter of terrorism around the world. He has suggested that the benefits flowing to Iran from the nuclear deal are reducing domestic economic pressures that could otherwise topple the oppressive regime.

“The sooner the president abrogates it entirely and creates a new international reality, the better,” Bolton said at a panel discussion on Iran in January. “I would without hesitation abrogate the nuclear deal, call the sanctions into effect.”

In August 2017, Bolton published a framework for exiting from the nuclear deal and indicated he was ready to help the White House develop a detailed action plan. He stressed the importance of laying the groundwork for an exit strategy before the president announces a final decision, presumably timed to coincide with one of his mandatory 90-day reviews of the deal.

Iran denounced Bolton’s appointment to national security adviser as “a matter of shame,” complaining that he has been supported by Iranian opposition groups that the government in Iran regards as terrorists.

Chinese economic and military aggression: Bolton arrives in the early stages of what is widely portrayed as a “trade war” between China and the United States. Investors are reportedly nervous that global markets could be severely disrupted as both Trump and Chinese President Xi Jinping find it politically impossible to back down from the confrontation.

Bolton has spoken approvingly of Trump’s trade actions against China, describing them as a much-needed dose of “shock therapy” in March.

“The Chinese have just been cheating, stealing intellectual property, discriminating against foreign investors and businesses. We’ve let them get away with it,” he said in a November appearance on Breitbart News Daily.

“There are so many people in the United States who have said for years that China is going to fit into international institutions, that it’s going to be a responsible stakeholder in global affairs, that it’s engaged in a peaceful rise. That scenario looks less and less like what’s really going on here,” he added.

Bolton is strongly critical of Chinese foreign policy as well, accusing them of cynically exploiting the North Korean nuclear crisis for political advantage. He has also warned of Chinese aggression in the South China Sea and towards Taiwan.

“We’ve got to confront this. China is threatening across a whole range of its periphery. We tend to think of China mostly in terms of trade deals, but it is a geopolitical threat, and it’s a rising threat,” he warned in December, counseling increased U.S. military spending to maintain naval superiority in the regions threatened by Chinese aggression.

Bolton is a strong supporter of Taiwan, saluting Trump for doing a “fantastic thing” when he enraged Beijing by taking a phone call from Taiwanese President Tsai Ing-wen in the early days of his administration.

Bolton has suggested challenging Beijing’s “One China” policy that forbids Taiwanese independence under threat of military action. Part of his proposal included selling more advanced weapons to Taiwan, and perhaps even stationing a significant number of American troops there, to inform Beijing that military action against the island is not an option.

Bolton is rumored to be considering a visit to Taipei in June, to attend the opening of the new headquarters for the unofficial American embassy to Taiwan. Beijing would likely express severe displeasure with such a visit.

Israel and the Palestinians: Bolton strongly approved of President Trump’s decision to shake up the stagnant “Palestinian peace process” by relocating the U.S. embassy in Israel to Jerusalem, a move he advocated long before the president ordered it.

“I just think this is one of these bubble-popping incidents where the president has defied the conventional wisdom and shown that it was completely hollow,” he said in December after Trump announced the embassy would move.

Bolton felt the embassy move would ultimately prompt some Middle Eastern powers to withdraw support from the Palestinians. “This is the sort of action by the president that actually constitutes American leadership in the world. American leadership does not consist, as Barack Obama thought it did, of doing what the Europeans want. It consists of doing what we think is right for the country and bringing the others along. I think that’s what Trump did yesterday,” he said.

Bolton believes the “two-state” solution long enshrined in Western foreign policy is a dead end and has suggested giving Gaza to Egypt while Jordan resumes control of the West Bank.

“The only logic underlying the demand for a Palestinian state is the political imperative of Israel’s opponents to weaken and encircle the Jewish state, thereby minimizing its potential to establish secure and defensible borders. The cruelest irony is that by using the Palestinian people as the tip of the spear against Israel, their supposed advocates have caused the Palestinians extensive suffering,” he wrote in an April 2014 op-ed for the Washington Times.

Bolton assumes the duties of national security adviser in the midst of violent mass demonstrations along the Israeli border by Palestinian groups, a gambit evidently designed to provoke an Israeli security response that the Palestinians and their allies could denounce as excessive. The death of a Palestinian journalist who was injured during a Palestinian assault on the Israeli border fence on Friday presents a new challenge for the Israeli government.

The Palestinians were infuriated by Bolton’s appointment to national security adviser.

“This man has a long history of hostility to Palestinians, dating to when he was at the United Nations, where he was protecting Israeli immunity. All this will lead to a devastating reality for Palestine and the region,” senior Palestinian official Hanan Ashrawi said in March.

Terrorism: Bolton frequently worries that terrorism is not taken seriously enough as a threat during the lulls between headline-grabbing terrorist attacks. He fears the continuing threat of the Islamic State is underestimated because the “caliphate” suffered such resounding military defeats in Iraq and Syria, noting that ISIS leaders and skilled terrorist operatives may have escaped to Libya, Afghanistan, Yemen, and other conflict zones.

Bolton believes the Muslim Brotherhood should have long ago been designated a terrorist organization by the United States, ascribing the delay to bureaucratic inertia and political correctness. He urged President Trump not to withdraw American forces from Afghanistan because of how quickly that country could once again become a stronghold of the Taliban and a base of operations for terrorist groups.

France is still reeling from the attack on a supermarket by an ISIS supporter in March. The vehicular homicide techniques pioneered by terrorists remain a reliable method of suddenly inflicting mass casualties, although in the latest example German authorities believe the perpetrator was not linked to organized terrorism.

Another disturbing threat is the resurgence of al-Qaeda, which skillfully rebuilt its power base and expanded its influence in Syria and other Middle Eastern conflict zones even as the Islamic State collapsed. Just two weeks ago, the U.S. military conducted its first airstrike against al-Qaeda positions in Libya, killing one of the terror group’s leaders.