The White House recently sought to enlist the Departments of Homeland Security and Justice to build a case for its controversial and unpopular immigration ban, CNN reported on Thursday. Among intelligence professionals, the request to produce analysis that supports a favored policy—vice producing analysis, and allowing it to inform policy—is called politicization. It is anathema to the training most analysts receive and the values that lie at the heart of the vocation. There is a high cost to putting ideology over informed assessments of political, economic, and military realities.

At the Central Intelligence Agency, where I served as director of strategy in the Directorate of Analysis, the subject of politicization is introduced to analysts almost as soon as they enter into service. There is good reason for this: Politicization is not an academic issue.

During the Cold War, the Ford administration convened a Team B comprised of conservative foreign-policy thinkers to challenge the intelligence community’s estimates of Soviet nuclear capabilities. Then-CIA director and future President George H.W. Bush later concluded the group’s work lent “itself to manipulation for purposes other than estimative accuracy.”

In the early 1990s, after a rocky confirmation process during which he was accused of politicizing intelligence analysis, Director of the CIA Robert Gates implemented a series of reforms aimed at guarding against political or ideological thinking coloring intelligence analysis. Gates described politicization as “deliberately distorting analysis or judgments to favor a preferred line of thinking irrespective of evidence.”

Recently—during my tenure as an analyst with the CIA—President George W. Bush’s administration exerted unusual pressure to have the CIA support its plans to invade Iraq because of that country’s alleged ties to al-Qaeda and its weapons of mass destruction program. Both assumptions proved flawed. Nada Bakos wrote about the problems with efforts to tie Iraq to al-Qaeda for Wired. An internal CIA post-mortem concluded that the CIA’s assessments of the Iraqi WMD program were a case of an effective denial-and-deception program that fed prevailing assumptions.

Intelligence analysis is more an imperfect art than it is a science: Gaps in reporting, bad sources, and circular reporting all complicate the analyst’s quest for knowledge and understanding. As a result, we have seen the rise of ideas like “words of estimative probability,” which, like any language, assume a degree of fluency that rarely exists.

Politicization, however, sits on top of all of these complicating factors because it is an act of willful commission: At its most overt, it amounts to using a political position to get people to say that a clear, bright blue sky is cloudy.

While the CIA prides itself on a tradition of “truth to power,” the reality of telling high-ranking officials that their beliefs are not supported by either the available reporting or the informed opinions of a cross-section of the analytic cadre is far more weighty than those three words convey. Speaking “truth to power” requires courage, because political partisans are all too happy to causally decry dissent as disloyalty.

What is the cost of politicization? As of 2013, it was estimated that the American invasion of Iraq in 2003 cost an estimated $1.7 trillion, and saw over 4,000 Americans killed in action and over 30,000 wounded in action. Those numbers don’t include the families of the fallen; the innocent Iraqis killed or wounded during the conflict; or the insurgency that evolved into the extremist threat that we now know as ISIS.

The irony is that President Trump is a vocal critic of his predecessors’ decisions to invade, occupy, and ultimately withdraw from Iraq. In the run-up to that war, the Department of Defense formed an Office of Special Plans, conceived by Deputy Secretary of Defense Paul Wolfowitz, which as Seymour Hersh argued in The New Yorker, “was created in order to find evidence of what Wolfowitz and his boss, Defense Secretary Donald Rumsfeld, believed to be true” about Iraq the threat it posed to the world. By trying to shape analysis to support his administration’s world view, Trump is creating the conditions for committing our country to courses of action that have the potential to be as costly or disastrous.

This administration may seek solace in reality-distorting “alternative facts,” but politicizing intelligence is a massive disservice to the American taxpayer. There are plenty of media outlets, web sites, and pundits that cater to the full spectrum of American political thought, to include those strains of belief that are more about subjective feelings than informed realities. Compelling the government’s cadre of professional analysts to partake in ideological fantasy will undermine America’s national security, not enhance it.