The U.S-led fight against the Islamic State group (ISIS) apparently isn't going too well, according to U.S. intelligence analysts.

But when those analysts reported their conclusions, their bosses inappropriately pressured them to alter their reports in order to portray the war in more optimistic light, according to The New York Times.

Several terrorism analysts allege that when their reports were too pessimistic about the Operation Inherent Resolve campaign, or if they questioned whether the U.S.-trained Iraqi military has what it takes to defeat ISIS, they were either asked to change the reports to portray ISIS as weaker than they actually are, or the reports were simply trashed rather than being shared with senior policymakers.

The Pentagon's inspector general has reportedly opened an investigation into the allegations.

One civilian Defense Intelligence Agency analyst told investigators that he had evidence that officials at United States Central Command (CENTCOM), which oversees the bombing campaign against ISIS in Iraq and Syria, were improperly editing the conclusions of intelligence assessments before sending them to policymakers, including President Obama, reported The Daily Beast.

Other analysts said they understood they were expected to provide conclusions that fell within a certain spectrum, and as a result, self-censored their own views.

"The phrase I use is the politicization of the intelligence community," retired Lt. Gen. Michael Flynn, the former director of the Defense Intelligence Agency, told The Daily Beast, adding that concerted efforts to skew the information in a positive light have increased over the past few months. "That's here. And it's dangerous," Flynn said.

The analysts told The Daily Beast it is unclear who exactly is leading the effort to pressure them into adjusting their assessments.

CENTCOM released a statement acknowledging that it does seek feedback from various intelligence agencies on assessments before publication, however, it said it does not have to incorporate the comments into the final report because it is the "primary agency" in the war.

"Further, the multisource nature of our assessment process purposely guards against any single report or opinion unduly influencing leaders and decision-makers," CENTCOM said, according to CNN.