Story highlights America is engulfed in a tsunami of unethical activity, Jeffrey D. Sachs says

Trump continues to mingle public interest and his personal business interests, he says

Jeffrey D. Sachs is university professor and director of the Center for Sustainable Development at Columbia University. The opinions expressed in this commentary are his.

(CNN) In a recent speech in Poland, President Donald Trump asked whether the West "has the will to survive." It's a good question, but aimed in the wrong direction. While Trump spoke about foreign aggression, the real threat to the West is the collapse of ethical norms, led by Trump and others like him. America is engulfed in a tsunami of unethical activity, and there is no assurance it has the will to save itself.

The most recent sign of this rot from within is the decision of a federal appeals court to reverse the conviction of former New York state Assembly Speaker Sheldon Silver. Silver got rich on bribes and kickbacks from individuals and companies doing business with New York state. He was tried, convicted and sentenced to 12 years in prison for fraud, extortion and money laundering.

Jeffrey D. Sachs

Yet the 2nd US Circuit Court of Appeals in Manhattan reversed the jury decision this month on the grounds that Silver's bribes and kickbacks didn't necessarily constitute crimes under federal precedents. They sent the case back to the lower court for retrial. (Silver's attorneys have denied he committed any wrongdoing.)

The court's "precedents" explanation reaches back to another case involving former Virginia Gov. Bob McDonnell. McDonnell and his wife, Maureen, asked for and received around $175,000 in payments from a Virginia businessman seeking regulatory favors from the state. The governor set up meetings, briefings and events so that the businessman could make his case to state officials. A jury in 2014 reached the obvious conclusion that Bob McDonnell was guilty of bribery.

Two years later, the US Supreme Court said no, he did not necessarily commit bribery, and vacated his conviction. There was nothing wrong, according to the twisted wisdom of the Supreme Court, with the good governor accepting enormous gifts from a constituent seeking favors from the state in return for the governor clearing a path for the businessman to make his pitch.