The news about President Donald Trump’s efforts to pressure Ukraine for dirt on a political opponent has piled up so quickly that everyone is struggling for a shorthand — not just a name to call the affair, but a historical analogy to understand it. The usual suspects do not seem to fit. The Ukraine initiative was not about a private matter, like President Bill Clinton’s scandal, or a domestic initiative, like Richard Nixon’s Watergate.

Instead, with each revelation Trump looks less and less like previous presidents and more like Oliver North, a National Security Council staffer who used the power of the White House to spearhead the operation that eventually became known as Iran-Contra. There are differences between the irregular president and a mischievous staffer, but as Fiona Hill, a former member of Trump’s own NSC, reportedly revealed in testimony Monday, both attempted to run rogue foreign policy operations from the White House with little oversight or respect for the law.

Sadly, as I’ve learned writing and promoting a book on the NSC, even those Americans who can recall North’s televised testimony to Congress are pretty fuzzy on Iran-Contra’s details. A comparison to that misbegotten mess will help everyone, including lawmakers, understand what went on in the Ukraine affair and why it went bad. Unfortunately, the contrast will also remind us it will take a lot more than Hill’s testimony to get to the bottom of it.

“A very thin line”

When news broke in November 1986 about what became known as the Iran-Contra affair, it began with a vague reference in a Lebanese magazine to new American outreach to Iran. That’s why the first misconception about the affair is that it started with Iran. But it really began years before, when North, a Marine lieutenant colonel assigned to the White House, began to support right-wing rebels, or Contras, battling the socialist government in Nicaragua. Only later did he and others sell arms to Iran, buying freedom for American hostages and illegally diverting some of the proceeds to the Contras.

North’s role on the president’s NSC staff was central to the whole scheme. Starting in 1982, Congress — worried about quagmires and overreach in the wake of Vietnam and Watergate — put express limits on support for the Contras. But the laws were written to bind the expected actors: U.S. intelligence agencies that had the experience and responsibility for these sorts of operations and were subject to congressional oversight. Instead, North and others found a loophole and figured the NSC staff, which does not answer to Congress, could do it.

That was, as one of North’s deputies in that initiative later said, “a very thin line.” For a while, North walked it well enough with a ragtag network of collaborators in government, consultants outside it (including former national security adviser Robert “Bud” McFarlane), shadowy foreign intermediaries, and private funders. Together, they covertly used U.S. military equipment, diplomatic relations, intelligence channels, and other government assets and personnel.

North finally crossed the line when he sent the Contras the proceeds of weapons sales to Iran—without Reagan’s approval and against Congressional limits. Eventually, North was convicted for his role in the affair and efforts to cover it up and others were indicted, though many were eventually pardoned and North’s conviction was later vacated. Rather than enact laws limiting the power of the presidency, Congress chose to trust that chief executives and their staff would remember that White House foreign policy operations were an inefficient use of government, were usually insufficient since the agencies had more experiences and resources, and could easily stray from the law.

“Drug deal”

This norm — that the White House should resist the temptation to carry out independent foreign policy operations — appears to have been cast aside by Trump and others when they pressed Ukraine for help against an American political rival. The president, and those directed by him inside and outside government including former New York Mayor Rudy Giuliani, appear to have promised and threatened diplomatic engagement with Ukraine. U.S. military aid was apparently withheld as a cudgel. Envoys and diplomats were assigned and reassigned, and the vice president and myriad U.S. agencies became involved (so far, we know of involvement by the Departments of State, Justice, and Energy).

There are of course some differences between Iran-Contra and the Ukraine operation, besides the relative rank of their respective protagonists. The first and most important is the relative legitimacy of each’s objective: Reagan’s team was trying to free hostages and aid anti-communists whereas Trump appears mostly focused on finding dirt on a rival. Besides the potential for obstruction, the laws at play also vary: North and company ran afoul of the limit on support for the Contras; Trump appears to have encouraged foreign interference in an election.

Yet the White House’s leadership is central to both operations. Indeed, Trump and North each misused the power of the presidency in unsettling ways: they issued orders, abused authorities, avoided oversight, and eventually crossed legal lines. They both also played active parts in carrying out the plots: Trump was on the phone and North flew to Tehran and more. Like Iran-Contra more than 30 years ago, Trump’s Ukraine initiative was, as Hill reportedly recalled yesterday, a “drug deal,” a scheme to get something done off the official books. For that reason, North worried about exposure in government and out, just as Trump and some of those close to him appeared to do the same.

“You deserve the truth”

To get to those details, Congress and others must remember that Washington did not learn about Iran-Contra merely by reading news reports from Lebanon, or anywhere else. Criminal inquiries, congressional probes, and a presidential review board spent years cracking open the government and compiling almost 50,000 pages of materials. To put that in perspective, the only 21 pages from the Ukraine affair released so far (the 5-page ‘transcript’ of Trump’s call with the Ukraine president plus 16 pages of the Whistleblower complaint) have set Twitter afire for almost two weeks.

The Iran-Contra investigations did so, in part, because even as North shredded documents with investigators waiting outside his office, Reagan committed to getting to the bottom of Iran-Contra. In an address to the nation, the fortieth president told the American people, “You deserve the truth.” As such, he decided against invoking executive privilege and instead offered some access to White House business.

Despite any hopes for a quick or contained inquiry into the Ukraine affair, a review of Trump’s operation will need to be just as massive and invasive. After all, few on Capitol Hill or around the country really understand how U.S. foreign policy is usually made, let alone how much Trump has perverted the regular order. That is one reason for the shock over Hill’s testimony last night.

To get to that central point, investigators must broadly expose the sausage-making of the national security business. They will have to consider issue areas as different as military aide and ambassadorial assignments, departments as dissimilar as Energy and Justice, and regions as unique as Europe and Asia. And they will need to talk with more than one White House aide: because of Trump’s hands-on role, any inquiry must pry open the White House and the NSC staff, inevitably leading to further confrontations over executive privilege.

As a result, like Iran-Contra before it, getting of the truth about today’s misguided foreign policy operation will not be easy and, unfortunately, it will not be cost free. Because of the Ukraine affair’s nature, today’s investigators will need to rip open America’s national security enterprise at a moment when officials are already struggling to keep up with a changing world in which new threats are emerging and old challenges persist. This is Trump’s fault, but given the nature of the issue and a proper investigation, we’ll all pay a price.