Washington (CNN) Earlier this summer, National Security Council experts were working to implement harsh penalties against Chinese technology behemoth ZTE when President Donald Trump caught them off-guard with a tweet about making deals with the foreign company.

Sources present in the Old Executive Office Building that day told CNN that after receiving a call from Chinese President Xi Jinping, Trump blindsided NSC officials by declaring he wanted to get ZTE "back into business," obliterating weeks of work by his staff who, until that moment, had been implementing the President's original agenda.

It is well within the President's authority to dictate foreign policy, but Trump's often impulsive handling of world affairs, unorthodox management style and general disdain for bureaucracy have, for better or for worse, fundamentally transformed the National Security Council.

Critics argue the NSC, historically the commander in chief's premier national security advisory body, has been "neutered" under Trump. Supporters say the council, made up of Cabinet officials and security experts who synthesize policies from across the government, has been streamlined to operate more efficiently.

Both critics and supporters say changes at the NSC have been kicked into overdrive by Trump's third national security adviser , John Bolton, leaving a swath of current and former national security officials worried that the former United Nations ambassador is undermining the NSC's critical role in helping a president mull all the options and make the best choices to keep the country safe.

Beyond Bolton, though, the most central figure in the council's evolution is the President himself. A real estate mogul with no prior foreign policy experience, Trump is uniquely positioned to need the NSC's expertise, even as he displays little interest in using it.

Bob Woodward's new book "Fear" depicts a national security team unnerved by the President's lack of knowledge or curiosity about world affairs, as well as his contempt for the views of military and intelligence leaders. Defense Secretary James Mattis is quoted saying Trump's understanding matches that of "a fifth- or sixth-grader."

Mattis later said the quotes attributed to him were "a product of someone's rich imagination."

That lack of curiosity and knowledge, coupled with the President's impulsiveness, might be the biggest obstacle to a properly functioning NSC, said Jamil Jaffer, a former associate White House counsel to President George W. Bush and founder of the National Security Institute at George Mason University's Antonin Scalia Law School.

"If key policy decisions are being made in real time at press conferences, press gaggles and on Twitter, it makes the NSC policy process significantly less effective," Jaffer said, "and dramatically reduces the ability of the President to get the best policy advice from his own staff as well as his Cabinet officials and executive departments."

Trump ignores advice and facts

Presidents have used the NSC in different ways since it was founded in 1947. Some, like Harry Truman, rarely attended NSC meetings, making major decisions with the help of only a few advisers. Others, like Barack Obama, have leaned heavily on its expertise.

Since taking office, Trump has demonstrated little interest in grinding policy discussions and grown increasingly impatient with long-winded national security briefings, resulting in an NSC that has been shrinking in size and influence over the course of his presidency, according to accounts from several current and former Trump administration officials.

Despite grappling with major challenges -- including North Korea, Russia and rising tensions with Iran -- Trump has demonstrated a tendency to react according to his own instincts and at times with a disregard for information presented by NSC experts, insisting instead on his own facts, according to former Trump administration officials.

Even though NSC officials limited multi-page briefings on key issues to three bullet points on a notecard, they rarely got the sense that Trump was reading and internalizing information, one former senior Trump administration official told CNN.

Instead, they found the President repeatedly ignored it, insisting, for example, that the US has a trade deficit with Canada, even though NSC officials assured him during several in-person briefings that, in fact, it has a surplus.

NSC officials have also sought to dissuade Trump of the notion that NATO members who have not met their commitment to devote a certain percentage of their gross domestic product to defense spending owe the US money.

"He was properly explained the process several times," one former senior administration official said, lamenting Trump's public and private insistence that NATO members are in debt to the US.

That has frustrated many current and former NSC officials, who have struggled to adapt to Trump's willingness to upend major policy initiatives at the drop of a hat.

Perhaps the most striking example of Trump's tendency to ignore his national security advisers was his disregard for their note telling him "DO NOT CONGRATULATE" Russian President Vladimir Putin for his victory in an election where the main opposition candidate was barred from running. He did anyway.

"Trump is ignoring his greatest asset and I'm very afraid of it atrophying," said Loren Schulman, a former Obama administration official who is now at the Center for a New American Security. Trump is "delegating as much as he can to agencies without giving them guidance or top cover and making decisions totally in the absence of advice."

An evolving role

Trump's White House moved to trim the NSC as part of an effort to distribute power back to military commanders, diplomatic officials and the national security agencies.

Trump's previous national security adviser, H.R. McMaster, along with former Secretary of State Rex Tillerson and Mattis agreed to limit the number of senior-level meetings, basically halving the number of times Cabinet officials and their deputies convened at the White House to just once and twice a week, respectively.

And the Pentagon and State Department instituted caps on how many career officials were allowed to be detailed out to the White House.

Bolton has accelerated the NSC's downsizing to the cheers of the President's supporters, slashing staff to under 300, with cuts across the board, officials say.

"Since his appointment in April, Amb. Bolton has made a number of needed adjustments to streamline the organization of the NSC and empower its staff," NSC spokesman Garrett Marquis told CNN.

Debate over the NSC's size started long before Trump and Bolton. In the early 1990s, President George H.W. Bush's NSC averaged about 50 people, according to the Congressional Research Service. After the wars in Iraq and Afghanistan, when some felt poor interagency coordination prevented Washington from consolidating gains after military victories, the NSC expanded to better coordinate US responses to complex global problems.

The NSC ballooned to around 400 staffers under Obama, who was heavily criticized for consolidating decision-making in the White House and micromanaging policy. It was recognized as a problem.

The Atlantic Council, a nonpartisan think tank, recommended reducing and restricting the NSC to 100 to 150 professionals, and House and Senate lawmakers included provisions in the 2017 defense bill to limit its size.

While it is ultimately up to Trump how he wants to use the NSC, Bolton is responsible for ensuring that the President at least has the opportunity to review all the critical information at his disposal.

However, many current and former Trump and Obama administration national security officials told CNN they are worried Bolton is pushing changes too far, undermining the NSC's critical role.

Part of critics' anxiety may be as much about Bolton's track record -- his advocacy for regime change and accusations that he manipulated intelligence in the lead-up to the Iraq War -- as it is about the role he now plays in shaping US foreign policy.

Officials at other agencies have complained that Bolton has all but abdicated his role in coordinating policymaking, even eliciting a formal protest from Mattis, who complained about the lack of Cabinet-level meetings.

Steve Bannon, the former White House chief strategist who played a central role in the foreign policy debates of the administration's first six months, said Bolton has indeed broken from the model McMaster followed, instead keying in on his role as principal foreign policy adviser.

"Under Generals Flynn and McMaster the NSC acted under more of the 'Scowcroft Model' -- as a curator for a robust interagency process," Bannon told CNN, referring to a two-time former national security adviser. Bannon, a longtime critic of the NSC who used his White House tenure to try to create a shadow national security advisory body for Trump, said Bolton better understands the President's agenda.

"Ambassador Bolton has a longer-term relationship with the President, and a better understanding of the 'America First' agenda," Bannon said. "I think he is acting as the senior adviser on national security matters."

A 'chaotic decline'

Bolton has also worked toward transforming the NSC into an entity that is hyper-focused on executing the President's agenda by bringing in more political appointees and reducing the number of career officials on his staff.

A senior administration official described the NSC downsizing that began under McMaster as a "controlled decline." Under Bolton, that official said, it has escalated into something much less ordered.

"It was an agreed-upon decline where more autonomy was given to the agencies," said one former administration official. "What's happening now is more of a chaotic decline."

Starting with Homeland Security Adviser Tom Bossert , axed upon his arrival home from a national security conference in Georgia, Bolton has fired, pressured or simply iced out a large number of senior NSC officials in the months since he started work.

One current official remarked to CNN that he was an "old man" for having worked at the White House for three months. The official said he was already looking for new jobs and being encouraged by his supervisor to return home to his parent agency.

At the moment, the NSC has over 30 open senior and deputy level jobs, and several positions and departments have been eliminated or merged, according to sources and public records.

Some argue that many of those vacancies, including positions focused on cyber and Middle East issues, are for essential jobs, given the national security threats facing the US.

The Bolton effect

While it is not unusual for an incoming national security adviser to hire people they can trust , sources tell CNN that NSC staff members, with the exception of a few handpicked aides and outside advisers, have had great difficulty even getting a meeting with Bolton in recent months.

"Everyone's asking for more meetings and guidance, and they're just not getting it," the former administration official said.

National Security Council spokesman Marquis insisted Bolton is refocusing the NSC to make policy coordination the council's central mission.

"The NSC continues to carry out its statutory mission to advise the President and coordinate the interagency process on all decisions related to national security," Marquis told CNN.

Those who support Bolton's efforts to reshape the NSC argue that its shrinking size allows senior officials to brief the President in a succinct way. Committee meetings come afterward to implement his decisions.

"It is a much more execution-oriented process," according to Jim Carafano of the Heritage Foundation. He noted that after a year in office, Trump has a general understanding of his policy objectives and wanted to surround himself with people he knew would work toward executing that vision.

"I don't think that means execute in a sense that no one is ever going to tell the President he's wrong, but people who agree their job is to execute the President's agenda," he said.

But that sequence may eliminate advice and input from agencies and career NSC officials, a key part of a bottom-up strategy, factoring in lower-level expertise, said one former NSC official.

"How is Bolton prepping for meetings with the President if he's not engaging with his own staff?" said CNN national security analyst Samantha Vinograd, who was an NSC official in the Obama White House.

She noted that meetings with NSC experts are intended to provide Bolton with the full scope of information related to a specific threat so he can then coordinate with relevant agencies to address them.