Washington(CNN) Former Secretary of State Rex Tillerson painted a scathing picture of his old boss President Donald Trump as someone who made uninformed decisions that were not based in reality -- a stark contrast to Trump's top diplomat Mike Pompeo, who is heaping praise on the outgoing President in his final days in office.
"His understanding of global events, his understanding of global history, his understanding of U.S. history was really limited. It's really hard to have a conversation with someone who doesn't even understand the concept for why we're talking about this," Tillerson said in a lengthy interview with Foreign Policy conducted prior to Wednesday's assault on the Capitol that was published this week.
Tillerson, who was ousted in March 2018, told the magazine, "I used to go into meetings with a list of four to five things I needed to talk to him about, and I quickly learned that if I got to three, it was a home run, and I realized getting two that were meaningful was probably the best objective."
He added that he "started taking charts and pictures with (him) because I found that those seemed to hold his attention better."
"I think the other challenge that I came to realize early on is there were so many people who had access to his ear who were telling him things, most of which were untrue, and then he began to listen to those voices and form a view that had no basis in fact," the former secretary of state said.
"So then you spent an inordinate amount of time working through why that's not true, working through why that's not factual, working through why that's not the basis on which you want to understand this, you need to set that aside, let's talk about what's real. I think that was as big a challenge as anything," Tillerson said.
Pompeo has devoted his Twitter feed in recent weeks to highlighting what he regards at the administration's achievements on the world stage and has not been shy about lavishing praise on Trump.
His laudatory statements, however, have faced renewed criticism by US diplomats in the last week who believe Pompeo's celebratory sentiments are jarring considering the tumult and violence which have marked Trump's final days in office, three US diplomats have told CNN.
On Wednesday morning, as the House was preparing to debate and vote on Trump's second impeachment, Pompeo tweeted suggesting that he should receive the Nobel Prize.
Pompeo also remained loyal and stood by Trump -- condemning the violent mobs, but in no way suggesting that Trump incited the insurrection -- while a handful of other cabinet secretaries resigned after the violent siege on Capitol Hill.
One primary difference that may explain the daylight between Pompeo and Tillerson: Pompeo has future political ambitions and Tillerson does not.
"Unfortunately for Tillerson he got a taste of politics and likely does not want anything to do with it ever again," said Douglas Heye, a GOP strategist. "But Pompeo is one of the people who wants to hitch his wagon to Trump's name and wants to continue to do so. What may be politically advantageous to Pompeo is that he can tout Trump's foreign policy successes and stay away from what happened last week because he has no ownership over it, whereas some of his Republican competitors like Josh Hawley and Ted Cruz do."
Tillerson, who has remained relatively quiet about his tenure as Trump's top diplomat, also made it clear that he is completely at odds with Pompeo when it comes to the Trump administration's China policy.
"We're nowhere with China on national security. We're in a worse place today than we were before he came in, and I didn't think that was possible," he said.
Tillerson said he believes China will be the biggest problem for the incoming Biden administration.
"I have a fear that we will come to military conflict with China within the decade and it will be when they make their move on Taiwan. They've been putting all of their pieces in place for a long time now to do that, and that is [Chinese President Xi Jinping's] legacy, to reunite China," he said.
Trump's China policy -- which turned overwhelmingly hawkish in the latter part of his presidency, particularly as he sought to cast blame on China for the coronavirus -- is viewed by Pompeo as one of the administration's greatest accomplishments.
Tillerson said he "could never understand" Trump's disparagement of allies.
"He saw those as people who were weak. He used to say that over and over again. I don't know why he viewed them as weak, other than they were overseeing free countries," he said.
Nor could Tillerson understand Trump's desire to woo adversaries, he said, noting that the President's meeting with North Korean dictator Kim Jong Un "was one of the last straws between him and I."
Although Pompeo was known to be privately skeptical of just how successful Trump's approach to Kim would be, sources told CNN, he never publicly said so. Instead, he has consistently supported Trump's approach and has even heralded Trump's meetings with Kim as effective even though they produced no tangible results on denuclearization of North Korea.