Almost two years ago, on Aug. 9, 2014, black teenager Michael Brown died under police gunfire in Ferguson, a suburb of St. Louis. Nearly two years later, on the evening of Thursday, July 7, an antiracist demonstration takes place in Dallas, during which five police officers are killed by a sniper right in the center of town. A new collective memory recalls the events of Ferguson that, perhaps, contributed to an awakening of the national conscience. However, this particular awakening is still far from having dismantled institutional and systemic racism.

"Reality has once again refused to let itself be ignored," wrote the American author Thomas Chatterton Williams on the heels of the massacre committed in June 2015 by a young neo-Nazi in an emblematic Methodist church in Charleston, South Carolina. Nine people lost their lives. Likewise, reality has once again refused to let itself be ignored with this week's deaths, at the hands of police officers, of Alton Sterling in Baton Rouge, Louisiana, and Philando Castile, on the outskirts of St. Paul, Minnesota.

Is it risky to draw a parallel between the abominable act committed by a neo-Nazi and the errors that police have committed against blacks? Certainly. Be that as it may, the so-called deranged mind of the man that discharged his weapon several times in the Charleston church is the — extreme — expression of a white society that struggles to dismantle its racist sentiments and constructs.

The murder of five police officers in Dallas adds another layer of violence and volatility to the racial tensions tormenting American society. Whether racial violence or violence plain and simple, it's not exactly an exaggeration to say that what happened on Thursday in Dallas — a few blocks from where J.F.K. was assassinated in 1963 — resembles a form of ancient, latent civil war. If the death of Michael Brown and the demonstrations that it triggered two years ago have contributed to a certain collective awareness, the fact is that arbitrary police abuse and harassment have always been the reality for the black minority — and this abuse has been committed in a widespread environment of impunity. To be a black citizen of the United States apparently means to risk finding oneself at any moment in the wrong place at the wrong time. Leaving San Francisco last year, Baltimore's new police commissioner gnashed his teeth, declaring that he had been shocked by the "1950s racism" that was prevalent in the service when he took his post in 2012.

Much of white America still chooses to live under the illusion that antisegregation laws adopted in the 1960s have eliminated the cultural and systemic discrimination toward the black minority — in health care, education, employment ... The election of Barack Obama as U.S. president has, for some, perpetuated the lie claiming that the United States is now a postracial society. It is, however, reasonable to think that we are witnessing the contrary, under an evidently less crude form of apartheid — a resegregation of the social and urban fabric of the country, amidst a worsening of economic inequalities stemming from the globalization of markets and the repercussions of the Great Recession.

Moreover, a growing number of studies have documented the racial prejudice of the justice system and police force toward blacks. A troubling statistic amply cited in the aftermath of Ferguson indicated that a young black man is 21 times more likely to be shot by the police than a young white man.

It turns out that until now, the ongoing chain of police errors committed in these last few years has not led to substantial change in the behavior of the authorities, and this is despite the increasingly widespread use of body cameras by police officers and the growing media coverage of injustice on all imaginable platforms. A Washington Post analysis indicates that, irrespective of racial origins, the number of individuals shot and killed by police officers in the United States is up by 6 percent since the beginning of the year, in comparison to 2015. A fresh statistic and the ensanguined subject of a video quickly gone viral, Philando Castile has thus become the 123rd black person to fall victim to police gunfire since the beginning of the year in the United States.

Consciences are easy to challenge; cultural behaviors and reflexes are more difficult to change.