John Gans is director of Communications and Research at the University of Pennsylvania's Perry World House. A former chief speechwriter at the Pentagon, he is also the author of "White House Warriors: How the National Security Council Transformed the American Way of War." Read more opinion at CNN.

(CNN) Although it remains to be seen what will come of the impeachment inquiry into President Donald Trump's alleged pressure campaign against Ukraine, Americans will have at least received in its earliest stage a lesson in how government really works. The difference between an ambassador and a chargé d'affaires has been explained . Most avid news consumers have now heard of a sensitive compartmented information facility, or SCIF. And everyone has learned how presidential phone calls work and sometimes don't.

That education continued last week as members of the powerful National Security Council staff began testifying . For over 70 years, NSC staffers have helped presidents with the big stuff, like wars, and the small, including meetings with other heads of state. Because of their unique position and purpose, it's no surprise congressional investigators want to talk to members of the NSC. But as new staffers come into the spotlight, Americans might be surprised that members of the President's NSC appear to be have taken different sides, and to have played different roles, in the confusing development of America's Ukraine policy under Trump.

NSC staffers have always had an unmatched view of how foreign policy is made. The National Security Council was created in 1947 to give the president an outlet to discuss the biggest foreign policy challenges facing the country with the secretaries of state and defense and others. Everyone knew the stakes of these sessions: The New York Times ran a two-page photo of one of the first meetings with the headline "The Men Who Guard the Nation's Security." Across from President Harry Truman at the table sat one of the first NSC staffers, who kept track of these confidential conversations and high-stakes decisions.

Over the years, the power and size of NSC staff, which is mostly made up of military officers, spies, and diplomats lent to the White House by agencies like the Pentagon, has grown. With advanced technology, presidents have been able to manage in real time America's wars and perform high-stakes diplomacy. The staff prepares the president for these sessions. They travel abroad on Air Force One. And as mostly everyone now knows, they listen in on calls with foreign leaders.

The staff is supposed to do all this anonymously. Presidents get most of the credit, blame, and attention, often followed by the Cabinet secretaries and the NSC staff's boss, the national security adviser. Staffers instead are found often just out of the news camera's frame and just below historians' radars. Because they are treated as staff, often they are also supposed to be beyond Congress's reach, their work shielded by classification and the concept of executive privilege.

Because staff stay so far behind the scenes, many assume they simply embody whatever a president wants. The truth has always been far more complicated and the staff's opinions more varied. There have been staffers who fought relentlessly to see their president's ideas carried out in Iraq and Afghanistan but also plenty who have disagreed with the commander-in-chief on those wars and many other policy matters. And there have been more than a few rogues along the way, including Oliver North, the Marine lieutenant colonel loaned to President Ronald Reagan's NSC, who later spearheaded the Iran-Contra affair.

The staffers working on Ukraine for President Trump reflect similar diversity. Alexander Vindman, a lieutenant colonel on loan to the NSC by the Army, appears to have been deeply worried by the President's dealings. Tim Morrison, a Republican hardline foreign policy expert said to be a nuclear hawk and an acolyte of former National Security Adviser John Bolton, was less concerned about the legality of the Ukraine scheme but decided to leave the staff before testifying last Thursday. Meanwhile, reports suggest Kashyap Patel, a former aide to the House Intelligence Committee Republicans with little experience on Ukraine, willingly served as a back-channel to the President in support of this scheme, according to The New York Times.

History is a reminder that such diversity is not novel, but what's unique about the Trump NSC staffers is that we are learning about them at all. Few NSC staffers, let alone their views on the president's choices, are really known to history: Indeed, North may be the only NSC staffer any American could name before this week. The NSC staff's growing renown, it turns out, is another sign of how abnormal Washington has become and how grave the President's actions on Ukraine appear to be.