BEIJING - In his landmark speech, "I have a dream," civil rights leader Martin Luther King voiced his strong aspiration for equal rights of the black people in US society.

Fifty years later, such a dream has been partially realized. The African Americans living in the United States today are enjoying elevated political and social status. Notably, the country is having its first African-American president in history.

However, despite the progress, racial divide still remains a deeply-rooted chronic disease that keeps tearing US society apart, just as manifested by the latest racial riot in Missouri.

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Stunned and enraged by the shooting death of an unarmed black teenager by a white police officer, a large number of residents in the suburban St. Louis town in Ferguson took to the streets and staged a tense standoff with police in riot gear.

In history, racial tensions cut deep in US society. Even now, the scar is obviously far from being fully healed.

Some might argue that racial differences and conflicts are unavoidable in a "melting pot" like the United States, where people from virtually every corner of the world converge and seek common lives.

However, it is undeniable that racial discrimination against African Americans or other ethnic minorities, though not as obvious as in the past, still persists in every aspect of US social lives, including employment, housing, education, and particularly, justice.

In the worst US violence in recent times, the acquittal of four white policemen in the beating of a black motorist in 1992 sparked a six-day riot involving thousands of people across the metropolitan area of Los Angeles, leaving an astounding 51 people dead.

In a highly-mixed society like the United States, such racial inequalities could only jeopardize social peace and security. It is highly advisable for the country to make extra efforts to effectively uproot racism in all fields so as to prevent tragedies from recurring.

The Ferguson incident once again demonstrates that even if in a country that has for years tried to play the role of an international human rights judge and defender, there is still much room for improvement at home.

In its annual human rights report issued in February, the United States assaulted almost 200 countries across the world for their so-called poor human rights records.

However, the US human rights flaws extend far beyond racial issues. As revealed by famous whistleblower Edward Snowden, the US government has hacked into emails and mobile phones of ordinary Americans as well as leaders of other countries, including traditional US allies.

What's more, Uncle Sam has witnessed numerous shooting sprees on its own land and launched incessant drone attacks on foreign soil, resulting in heavy civilian casualties.

Each country has its own national conditions that might lead to different social problems. Obviously, what the United States needs to do is to concentrate on solving its own problems rather than always pointing fingers at others.