The recent shooting deaths of eight police officers in two separate incidents has shocked the nation and left us searching for answers.

On Sunday morning, Gavin Long engaged in a shootout with police in Baton Rouge that left three officers dead and three injured. Long was also killed.

Just 10 days earlier, on the night of July 7, Micah Xavier Johnson drove to a Black Lives Matter protest in downtown Dallas, Texas, determined to kill white police officers. He killed five policemen and wounded seven others before he was killed after a long standoff with law enforcement.

While we may never fully know what caused Johnson and Long to commit such horrific crimes, the fact that they were both African-Americans and served in the military has received significant attention.

Johnson has been variously described as “demented,” a “disgrace” and filled with hatred. Initial reports suspect Long suffered from “paranoia” and “mental instability.”

African-Americans have a long and proud history of participation in the United States armed forces. Black soldiers have fought in every war from the American Revolution to the present. I have written about their important role in World War I. They are powerful symbols of black patriotism and respectability, and demonstrate how in spite of slavery, Jim Crow and institutionalised discrimination, African-Americans have been willing to fight for their country and die for its ideals.

Micah Johnson and Gavin Long violently disrupt this narrative. Their actions speak to a rarely acknowledged aspect of the history of African-American veterans – one of injustice, disillusionment, trauma, racial militancy and undignified death. Johnson, Long and their troubled humanity remind us that the history of black servicemen and women has been fraught with tension.

The meaning of service

Johnson and Long were dedicated soldiers. Johnson’s mother, Delphine Johnson, said that her son, like so many black servicemen before him, “loved his country” and wanted to protect it. Johnson served in the United States Army Reserves for six years, enlisting out of high school in 2009. He completed a tour of duty in Afghanistan with the 420th Engineer Brigade before receiving an honourable discharge in 2015.

Long was a former US Marine who served for five years – including one year in Iraq as a data specialist. He achieved the rank of sergeant until his discharge in 2010. He received several awards during his time in the Marines, including a good conduct medal.

Like Long and Johnson, black men and women have joined the military for various reasons throughout American history. While love of country has been an important motivation, other factors such as the opportunity for freedom, the desire for adventure and the promise of gainful employment have also been meaningful. More than just patriotic symbols, black servicemen and women, like all individuals, possess complex identities that have shaped their military experiences.

Disillusionment and trauma

These experiences have not always been positive.

According to his family, Johnson returned home from Afghanistan a different person. “The military was not what Micah thought it would be,” Johnson’s mother has stated, adding, “He was very disappointed, very disappointed.” In her words, he became “a hermit” and resentful toward the government.

After his discharge, Long also seems to have become isolated and aggrieved. He divorced his wife, changed his name to “Cosmo Setepenra,” accused the government of placing him under surveillance and in numerous online videos decried systematic racism against African-Americans, including the July 5 police killing of Alton Sterling in Baton Rouge.

Johnson’s mother said that “it may be that the ideal that he thought of our government, of what he thought the military represented, it just didn’t live up to his expectation.”

In the longer historical context of African-Americans in the armed forces, Johnson would not be alone. For much of its history, the military has been a deeply racist institution. Black soldiers, having to endure often virulent discrimination and abuse, naturally questioned the value of risking their life for a nation that refused to respect both their American identity and basic humanity.

Studies have shown that black soldiers suffer from higher rates of Post-Traumatic Stress Disorder than their white counterparts. However, many black veterans suffer the added trauma of their disillusioning experiences in the armed forces and the cognitive dissonance between the ideals and reality of the United States, especially in regards to race. African-American veterans have often questioned how they could fight for freedom and democracy abroad while still confronting racism at home.

It is fair to ask: How did serving in Iraq and Afghanistan, and then seeing videos of police killing unarmed black people, possibly affect Long and Johnson’s respective psyches? Both men may not have served in combat, but they would not be immune from the psychological traumas of being black soldiers and the need to make sense of this conflicted identity at a time of heightened racial tensions.

Black radicalism and the spectre of violence

That Long and Johnson apparently exhibited a stronger sense of racial militancy following their discharge should not be surprising.

Black veterans constitute an important part of the history of black radicalism in the United States. While Long and Johnson appear to have had no formal affiliations and likely acted alone, examples abound of African-American veterans participating in and leading militant organisations committed to black freedom and racial justice.

Following World War I, many disillusioned black veterans joined groups such as the African Blood Brotherhood and, most notably, Marcus Garvey’s Universal Negro Improvement Association. Former soldiers played a significant role in the Civil Rights and Black Power movements of the 1960s. Ernest Thomas, a veteran of World War II, founded the Deacons of Defense that provided armed protection for southern civil rights activists. The Black Panther Party was cofounded by Bobby Seale, who served three years in the United States Air Force until he was dishonourably discharged for fighting.

The connection among African-American veterans, black militancy and the specter of violence is also not new. Historical fears of radicalised black soldiers and veterans sparking racial conflict – especially in the South – and killing white people date back to the Reconstruction era and continued following World War I and World War II.

The Dallas and Baton Rouge shootings also invoke memories of more modern incidents. In 1973, a disgruntled black Navy veteran, Mark Essex, murdered nine people, including five police officers, in New Orleans. Essex’s rampage ended when law enforcement trapped him on a hotel roof and filled his body with over 200 bullets. Micah Johnson met a similarly grisly fate when he was cornered by Dallas police in a parking garage and killed by a robot-delivered bomb.

Should we mourn for Micah Johnson and Gavin Long? Did their lives matter? Do their violent actions erase the meaning of their years of military service? Do we ignore their humanity?

The actions of Johnson and Long are inexcusable. They do not represent the Black Lives Matter movement. They certainly do not represent the millions of black veterans, past and present, who served their country and as civilians have made valuable contributions to society.

But there is also no denying that Johnson and Long speak to a more unsettling historical reality, that for many black veterans the nation they swore to protect and defend has ultimately failed them by not sufficiently protecting and defending black people.

This makes them American tragedies.

Chad Williams, Associate Professor of African and Afro-American Studies, Brandeis University.

This article first appeared on The Conversation.