WATCH: Bush just delivered a stunning 16-minute repudiation of Trumpism -- without ever mentioning his name

Former President George W. Bush warned Thursday that the United States of America was being ripped apart by external and internal strife -- citing both Russian operations and white supremacists.

"Parts of Europe have developed an identity crisis," Bush said in a speech sponsored by the George W. Bush Institute in New York. "We have seen insolvency, economic stagnation, youth unemployment, anger about immigration, resurgent ethno-nationalism and questions about the meaning and durability of the European Union. America is not immune."

"In recent decades public confidence in our institutions has declined, our governing class has often been paralyzed in the face of obvious and pressing needs, the American dream of upward mobility seems out of reach to some who feel left behind in a changing economy, discontent deepened and sharpened partisan conflicts, our politics seems more vulnerable to conspiracy theories and outright fabrication, there are some signs that the intensity of support for democracy itself has waned -- especially among the young."

"We've seen our discourse degraded by casual cruelty. At times it can seem like the forces pulling us apart are stronger than the forces binding us together. Argument turns too easily into animosity, disagreement escalates into dehumanization," Bush continued.

The former Republican president then referenced a number of issues that have circulated around President Donald Trump and his supporters.

"We've seen nationalism distorted into nativism, forgotten the dynamism immigration has always brought to America, the fading value of trade, we've seen the return of isolationist sentiments forgetting that American security is directly threatened by the chaos and despair of distant places where threats such as terrorism, infectious disease, criminal gangs and drug trafficking tend to emerge. In all these ways, we need to recall and recover our own identity."

Bush said the United States needed to harden its defenses against Russia, which has used social media in a disinformation campaign targeting Americans. He also said the U.S. government needed to ensure its voting system was protected from cyber attacks.

"America has experienced a sustained attempt by a hostile power to exploit our country's divisions and feed them. According to intelligence services, the Russian government has made a project of turning Americans against each other," Bush said.

"Foreign aggressions including cyberattacks, disinformation and financial influence should never be downplayed or tolerated," he added.

The former president also described white supremacy "in any form" as a "blasphemy against the American creed."

"Our identity as a nation, unlike many other nations, is not determined by geography or ethnicity, by soil or blood," he said, referencing a chant used by neo-Nazis during a march in Virginia.

"Being American involves the embrace of high ideals and civic responsibility," Bush remarked. "We become the heirs of Thomas Jefferson by accepting the ideal of human dignity found in the Declaration of Independence, we become the heirs of James Madison by understanding the genius and values of the U.S. constitution, we become the heirs of Martin Luther King Jr. by recognizing one another not by the color of their skin but by the content of their character. This means that people of every race, religion and ethnicity can be fully and equally American."

Bush also warned that some American leaders were not acting like positive role models.

"Bullying and prejudice in our public life sets a national tone, provides permission for cruelty and bigotry, and compromises the moral education of children. The only way to pass along civic values is to first live up to them."

Watch his full speech below: