Iranian officials Sunday described President Trump's decision to appoint John Bolton national security adviser as shameful and a sign that Washington intends to overthrow the Tehran theocracy.
In Afghanistan, McMaster took a similarly tough line, pressing Trump to agree, against his own instincts, to double the size of USA forces to 15,000 troops and back a strategy that relies heavily on America's ability to improve Afghanistan's inefficient and corrupt government.
The national security shakeup comes as the president is increasingly shedding advisers who once eased the Republican establishment's concerns about the foreign policy and political novice in the White House. Ricky Waddell, who was close to McMaster, is also expected to be dismissed by John Bolton.
Bolton, a Fox News commentator and prolific writer, brings a coherent and unusually controversial foreign policy philosophy to the White House.
Among other things, Bolton has recently argued the US should launch a "preventive attack" on North Korea before it develops the capability to strike the USA with a nuclear weapon. He said leaks "interfere with the president's ability to come to conclusions after discussing all the options in private".
With fewer "moderating voices" in the White House, however, should Trump seriously consider a military strike on the North, Bolton would likely "enhance Trump's instincts rather than counsel caution", he added.
McMaster had told confidants he would leave the post if at any point he lost credibility on the global stage, according to three White House officials. The story caused Trump to speed up McMaster's departure, the sources said.
Chief of staff John Kelly and Defense Secretary Jim Mattis had been pushing Trump to get rid of McMaster and had been escalating their campaign in recent weeks.
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"Just spoke to @POTUS and Gen. H.R. McMaster - contrary to reports they have a good working relationship and there are no changes at the NSC", White House press secretary Sarah Huckabee Sanders tweeted a week ago.
The revolving door in the West Wing was swinging quite a bit this week. No suitable postings had been identified, leaving McMaster long an iconoclast among the top brass with no choice but retirement.
That has veterans of the Trump administration predicting that Bolton will quickly seek to install his own team at the NSC, which functions as a clearing house for policy advice and is supposed to integrate the different perspectives of US government agencies.
Pressure group Human Rights Watch has denounced Pompeo as a defender of torture and discrimination against Muslims and homosexuals and wrote to urge the Senate to reject his appointment.
Trump's first national security adviser, Michael Flynn, was sacked for lying about contacts with the Russian embassy and has since pleaded guilty for making false statements to the Federal Bureau of Investigation.
Now, if Trump decides to abandon the Iran nuclear deal he has an adviser who thinks Iran can be disarmed by force-and was one of the principal players who pushed for the 2003 invasion of Iraq. "Trump likes the pugnacious, tough-guy style, and they reinforce it", said Eliot Cohen, a former Bush administration official and Trump critic.
"General McMaster forgot to say that the results of the 2016 election were not impacted or changed by the Russians and that the only Collusion was between Russia and Crooked H, the DNC and the Dems", Trump tweeted February 17, alluding to frequent GOP allegations of impropriety by Democrats and Hillary Clinton. In his first year in office, Trump surrounded himself with foreign policy aides whose views spanned a wide spectrum.
This file photo shows incoming U.S. National Security Adviser John Bolton. White House officials said he was ousted because he did not tell top advisers, including Vice President Mike Pence, about the full extent of his contacts with Russian officials.