Peter Bergen is CNN's national security analyst, a vice president at New America and a professor of practice at Arizona State University. He is the author of "United States of Jihad: Investigating America's Homegrown Terrorists." The opinions expressed in this commentary are his own. View more opinion articles at CNN.

Bolton was a prominent proponent of the Iraq War and he has never evinced any doubt about the wisdom of that decision, telling the Washington Examiner four years ago, "I still think the decision to overthrow Saddam was correct."

By contrast, last year President Trump said the Iraq War was "the single worst decision ever made."

Just before he was installed a little over a year ago as Trump's national security adviser, Bolton advocated for a pre-emptive war against North Korea in the Wall Street Journal.

The US government is now ramping up tensions with the volatile North Korean regime, announcing Thursday that it had "recently" taken into custody a North Korean ship that was defying sanctions on the nuclear-armed state -- the first time the US has taken such an action.

But Trump's general approach on North Korea has been to engage in negotiations with its leader, Kim Jong Un.

In recent weeks Bolton pushed for a coup in Venezuela involving opposition leader Juan Guaido that was believed to have the backing of key officers of the nation's military. The US-backed uprising seems to have fizzled.

On Thursday, President Trump said that he actually moderates the bellicose Bolton: "I'm the one who tempers him, which is OK. I have John Bolton and I have people who are a little more dovish than him."

Bolton's enthusiasm for the muscular use of the military seems out of place in the administration of a President who has repeatedly questioned and sought to end America's wars in the Middle East.

Yet while Trump and Bolton may be out of step with each other on policy toward Venezuela and North Korea, one country they both had been on the same page about is Iran, at least until recently. Trump and Bolton have voiced serious criticism of the Iranian regime, but in recent days Trump has said he is willing to talk to Iran and has told associates that he is irritated by Bolton's bellicosity towards Iran, according to sources cited by CNN.

Bolton's long history of deep conservatism

Bolton, 70, has espoused deeply conservative views since he was a teenager. The son of a Baltimore firefighter, Bolton worked on the Barry Goldwater Republican presidential campaign in 1964, and he later interned for President Richard Nixon's vice president, Spiro Agnew. Bolton went to Yale and then to Yale Law School. He has worked in Republican administrations since Ronald Reagan's first term.

Bolton has long rejected any constraints on American power. The happiest moment Bolton had when he was working for the US State Department was when he "unsigned" the agreement that made the United States a party to the International Criminal Court, which he saw as a risk for US political and military leaders who might be charged with war crimes. After Bolton pulled the United States out of the agreement in 2002, he said he felt like a kid on Christmas Day.

When Bolton became Trump's national security adviser, he ensured that anyone on the International Criminal Court who was investigating American soldiers or intelligence officials for possible war crimes in Afghanistan was denied visas to the United States.

Bolton's dislike of the Iranian regime is longstanding. In 2015, Bolton wrote in the New York Times that the United States should bomb Iran because "Iran will not negotiate away its nuclear program," which is exactly what Iran did that same year when it negotiated an agreement with the Obama administration to halt its nuclear weapons program.

The New York Times reported Monday that Bolton has ordered up military options that were presented to top Trump national security officials last week. They include the potential deployment of as many as 120,000 American troops to the Middle East if Iran attacks American targets in the region or resumes work on its nuclear weapons program.

Conflict with Iran?

The United States is now getting closer to war with Iran than at any time in decades, a process that began with the unraveling of the Iran nuclear deal last year.

Former US Secretary of State Rex Tillerson, Trump's previous national security adviser H.R. McMaster, and former Secretary of Defense Jim Mattis all advocated for preserving the Iran nuclear deal on the basis that a regionally aggressive Iran without nuclear weapons was a better prospect than a regionally aggressive Iran armed with nukes.

The deal meant that Iran was not able to begin to enrich uranium until 2030.

The International Atomic Energy Agency has repeatedly certified that Iran has stuck to the terms of the nuclear deal.

On October 3, 2017, Mattis, long known for his hawkish views on Iran, testified before the Senate Armed Services Committee that Iran was sticking to the nuclear agreement. When Sen. Angus King of Maine asked Mattis whether he thought the deal was in US national security interests, he replied , "Yes, senator, I do."

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Less than a month after Bolton became national security adviser, the US pulled out of the Iran deal. Trump announced on May 8, 2018, that he was pulling out of the Iran nuclear agreement. As Bolton stood off to one side behind him, Trump gave a press conference at the White House announcing the pullout, saying, "The fact is that this was a horrible one-sided deal that should never, ever been made."

The US pullout from the Iran deal was followed by the US putting new sanctions on Iran. The other parties to the agreement -- Britain, France and Germany, as well as China and Russia -- have remained in the deal.

Last week, Iran responded to the new US sanctions by saying that it would start pulling out of parts of the nuclear deal.

Around the same time, US officials briefed reporters about intelligence suggesting Iran or its proxies were planning to attack American forces in Iraq and Syria.

A British general based in Iraq who is the No. 2 commander in the US-led anti-ISIS coalition contradicted that assessment on Tuesday, saying that there was "no increased threat from Iranian-backed forces" to US forces or their allies in Iraq and Syria.

A US Central Command spokesman then rebutted the British general on Tuesday, saying his comments "run counter to the identified credible threats available to intelligence from US and allies regarding Iranian-backed forces in the region."

On Sunday, two Saudi oil tankers and two other ships were attacked in the Strait of Hormuz in the Persian Gulf. The Wall Street Journal reported that US intelligence has made an initial assessment that Iran was behind the attacks

Iran's Foreign Ministry says the attacks were "alarming and regrettable," implying that Iran wasn't responsible for them.

On Tuesday, armed drones attacked oil facilities in Saudi Arabia, according to the Saudi government. Iran-backed Houthi forces in neighboring Yemen have repeatedly launched missiles and drones at Saudi targets.

As a result of the increasing tensions with Iran, Bolton announced on Sunday that the United States was deploying a carrier strike group and a bomber task force to the Middle East.

Winston Churchill, who fought in a number of wars and led his nation to victory in the most lethal conflict in history, observed that talking was always better than fighting : "To jaw-jaw is better than to war-war."

Bolton, who avoided serving in Vietnam by going to law school and joining the National Guard, seems to have reversed Churchill's maxim: "Better to war-war than to jaw-jaw."

Note: This article has been updated with news of President Trump's latest views on Iran.