On Veterans Day this past week, President Trump declared that his decision to go to war with Iran had been a complete success.
“When this conflict is over, and it will be soon,” he said, speaking on a blustery morning from Arlington National Cemetery outside Washington, “the entire world will be a much safer and better place, more peaceful place.”
That is not how it feels in Europe.
A growing number of attempted terrorist attacks across the continent and in Britain, including a foiled plot against a major American military base, arson attacks on Jewish community sites and cyberattacks that raised temperatures in refrigerators and blood banks are rattling national security officials and unnerving the public. Many have been attributed to Iran or to proxies acting on its behalf.
The sense of global unease was heightened when the U.S. government grounded all air travel for hours on Friday in what officials later said was a technical issue.
European residents had already grown frustrated before the most recent round of turmoil. The economic consequences of the war that Mr. Trump and the Israeli government started against Iran in February have piled up: Gas prices are higher because of disruptions of oil deliveries through the Strait of Hormuz. Groceries cost more. Heating homes in winter has become far less affordable.
And in recent weeks, the effect has grown darker as security officials have accused Iran or its proxies of conducting a series of terrorism-related plots. In September, U.S. prosecutors say, an Iraqi man, an Iranian operative and a senior operative for an Iran proxy group in a New York jail plotted to attack R.A.F. Fairford, an air base in England used by American bombers. They did not succeed, but the effort prompted a major security incident.
In October, grocery store refrigerators in France were hit by a cyberattack that rotted millions of dollars’ worth of food, a tactic repeated this month in some supermarkets in Belgium, Luxembourg, Sweden, Ireland, the Netherlands, Estonia and Finland. Several French blood banks were also hacked. On Monday, France accused Iran of orchestrating the refrigerator attacks in its country, calling it a large-scale cyberattack aimed at sabotage.
From the beginning, political leaders across Europe were eager to avoid being dragged into Mr. Trump’s war.
Officials in Spain, Germany, France and Britain all declared they would not take part in America’s offensive attacks on Tehran, even as some host American military bases. Despite that, they appear to have become collateral damage as Iran seeks to show the consequences if Mr. Trump resumes aggressive actions.
“Iran is signaling very clearly to the Europeans that if the U.S. resumes the war, Europe is going to also become part of the target list for counter escalation,” said Ellie Geranmayeh, a Middle East and North Africa expert at the European Council on Foreign Relations. “It’s a sign of Iran’s desperation that they are trying to drag the Europeans into this global pain.”
Gen. Roly Walker, the chief of the general staff in Britain, told troops last month that “there is extreme jeopardy in the world at the moment,” adding that “very soon, the political leaders of this country will start to have a frank conversation with the citizens of this country, about just what is going on and where the risk lies.”
Of course Iran is not the only source of threats in Europe. Russia’s war of aggression in Ukraine has led to an increasing number of sabotage operations, including the jamming of aviation signals over Sweden, drones flying over Danish and Belgian airports and the smuggling of explosives into Poland in cans of corn. Western officials accuse Russia of trying to undermine European support for Ukraine.
Not all of the disruption has a clear origin. This past week, bomb threats were emailed to thousands of schools in Italy, forcing hundreds of them to be evacuated. That came after planes in Italy, Poland, Spain and elsewhere were grounded or diverted because of bomb threats that turned out to be hoaxes. Officials have not determined who was behind the threats.
As of Saturday, American officials said the decision to ground all flights in the country for several hours, which also affected flights at London’s Heathrow Airport and other international hubs, did not appear to be the result of a cyberattack. Officials at the U.S. Department of Transportation said they issued the temporary ban on flights because of failures in the system’s “antiquated, legacy communications equipment.”
But intelligence officials are increasingly concerned about retaliation by Iran’s government in response to the attacks by the United States and Israel.
In his annual threat update last month, Ken McCallum, the director general of MI5, said that Iran has shifted its ambitions to attack “harder targets, like military sites.”
On Sept. 27, the police apprehended five British men as they drove three vans near R.A.F. Fairford, the air base that hosted American bombers flying sorties to Iran. Two individuals were later charged with national security offenses over the plot, with prosecutors saying they believed it was orchestrated by a man believed to be working for the Iranian state.
Iran has forcefully denied any involvement in the Fairford plot.
More light was shed on the plot in a federal grand jury indictment unsealed in New York this past week, which provides a window into Iran’s efforts to conduct what the document calls the “European terrorist attacks.”
The indictment says the attempted attacks were directed by Mohammad Baqer Saad Dawood al-Saadi, a commander of Kataib Hezbollah, an Iraqi militia that is one of Iran’s most powerful proxies. According to investigators, Mr. al-Saadi helped plan and initiate the Fairford attack while in prison in New York, where he had been charged with plotting attacks on Jewish institutions in Europe, including London.
After the foiled attack at Fairford, the United States quickly withdrew all 12 of its B-1 Air Force bombers from the air base. Officials said they had received new threats about an Iran-backed plot against the installation.
As many as a dozen U.S. military aircraft were also evacuated from R.A.F. Mildenhall in England this past week, with officials saying they had detected an Iran-backed drone plot.
Security officials and analysts said the Iran-backed plots in Britain were likely prompted by the heavy presence of American forces and planes that were used in the attacks on Iran at the beginning of the war.
Keir Starmer, who at the time was the British prime minister, did not join the war with Iran and blocked the United States from using its British bases for offensive attacks. But after initial hesitation, he allowed what he called “defensive” bombing campaigns by American forces against Iran, saying they were necessary to protect British and allied interests in that region.
Soon after that decision, the Joint Terrorism Analysis Center in Britain raised the terrorism threat level to its second-highest level: “SEVERE — an attack is highly likely.” At the time, officials cited “a series of arson attacks and incidents against British Jews and opponents of the Iranian regime,” along with other incidents.
In recent months, Iran appears to have broadened its targets to include countries — like France — which did not host American military forces used in the war. The U.S. State Department has issued “Level 2” travel advisories for many European countries, urging travelers to “exercise increased caution” because of the threat of terrorism.
Viktorija Rusinaite, the director of research and analysis at the European Center of Excellence for Countering Hybrid Threats in Helsinki, Finland, said the targets of Iran’s terrorism threats have changed in the past nine months.
Before the war with Iran began in February, Ms. Rusinaite said, Iran tended to initiate attacks on Iranian dissidents and opposition figures living abroad, along with American and Israeli targets. Now, she said, the Iranian security system appears more willing to go after European targets more broadly.
“This seems to be changing right now,” she said. Before the war, she added, “they would see, for example, opposition or free media as a threat to regime survival. They’re now seeing that some of the European countries might threaten regime survival as well.”
Ms. Rusinaite said it was also possible that cooperation between Russia and Iran, including trade in military weapons and expertise, could “strengthen Iranian hybrid threat capabilities and might make things more complicated for European security officials.”