The countries will negotiate next week through intermediaries in Vienna to try to bring both back into compliance with the 2015 nuclear agreement.

When the Internet began to flourish in the 1990’s, there was an assumption that it would foster the values that the United States and its European allies held dearest: Freedom of expression, the spread of democracy, the empowerment of the individual. Presidents, prime ministers and German chancellors embraced the idea that the world’s democracies would be bound together, and that over time greater connectivity would enhance not only trade and understanding, but the alliance. 

Now, a new reality is dawning.

Harvard Kennedy School (HKS) and the German Council on Foreign Relations (DGAP) convened a strategy group of experts and former government officials from the United States and Europe over the past year to discuss the crisis in the transatlantic relationship and to propose a strategy to revive and strengthen it.

The killing of Iran’s top nuclear scientist is likely to impede the country’s military ambitions. Its real purpose may have been to prevent the president-elect from resuming diplomacy with Tehran.

The intelligence finding that Russia was most likely paying a bounty for the lives of American soldiers in Afghanistan has evoked a strange silence from President Trump and his top national security officials on the question of what to do about the Kremlin’s wave of aggression.

Mr. Trump insists he never saw the intelligence, though it was part of the President’s Daily Brief just days before a peace deal was signed with the Taliban in February.

President Trump opened a small window for diplomacy with Iran on Wednesday, but combined his words with bald threats that made it hard to see how the two countries could break out of their cycle of confrontation and revenge.

Rudolph W. Giuliani, the former New York mayor at the center of the impeachment investigation into the conduct of Ukraine policy, makes a living selling cybersecurity advice through his companies. President Trump even named him the administration’s first informal “cybersecurity adviser.”

The last two impeachment investigations of the past half-century began with a third-rate burglary and an extramarital affair. They quickly expanded to question the credibility and ethics of the president, but never touched on America’s national interests in the weightiest geopolitical confrontations of their eras.

President Trump is pushing Boris Johnson, the incoming prime minister of Britain, toward a hard break with the European Union. But Mr. Johnson could be constrained.

President Trump and his aides have sent a dizzying, seemingly conflicting set of messages to Iran in recent weeks, ordering more troops to the Middle East and a carrier to the Arabian Sea as military threats even while declaring that Washington is seeking new negotiations, not war.