The European Union spent last year drawing up secret plans for what the bloc would do if President Trump made good on his threats of imposing higher tariffs on European goods and services.

Now, as those threats go from hypothetical to potentially imminent, its plans are coming into broad focus.

Hit specific, politically sensitive sectors — like products made in Republican states — with targeted tariffs meant to inflict maximum pain. Don’t escalate into a tit-for-tat competition if it’s avoidable. Do move quickly and decisively, potentially using new tactics that could hit service providers like big Silicon Valley technology firms.

It’s a rough playbook — described broadly by three diplomats who requested anonymity because the plans were still being discussed — that Europe would prefer not to use. The first goal is to avoid a trade war by offering to negotiate and dangling carrots, including more European purchases of American gas, which Mr. Trump has been pushing for. E.U. officials have warned that a trade war between the bloc and the United States would be a self-defeating disaster that would cost both sides and benefit geopolitical rivals like China and Russia.

But Mr. Trump has kept the continent in his cross hairs, saying this week that the bloc would “definitely” face tariffs and “pretty soon.” If appeasement fails, Europe is broadcasting that it is ready to hit back.

“We are prepared,” Ursula von der Leyen, the president of the European Commission, said during a news conference this week in Brussels, when asked whether she was ready to fend off tariff increases from the new U.S. administration.

The commission, the bloc’s executive arm, has remained tight-lipped about what products it might hit with higher tariffs even when it meets with ambassadors and other diplomats from E.U. countries, said the three diplomats, who were briefed on the broad ideas developed by the so-called Trump task force. The bloc has 27 member countries, and plans that are shared too widely are likely to leak, eliminating their strategic advantage.

But several guiding principles are increasingly clear, said two of the diplomats, the result both of work by the commission’s task force and of experience gleaned from Mr. Trump’s first term. The diplomats requested anonymity to discuss politically sensitive matters.

The first idea is that tariffs would most likely be targeted, whether that means placed on certain industries or geography-tied products. In 2018, for instance, Europe reacted to steel and aluminum tariffs by hitting American whiskey with a large tariff, which hurt Kentucky’s bourbon industry and, thus, a constituency critical to Mitch McConnell, a Kentucky Republican who was then the Senate majority leader.

A second idea is to stagger the response, kicking in or ratcheting up retaliation only if certain triggers are met or dates passed, two of the diplomats said. Moving deliberately provides more leverage, one diplomat said, and avoids an immediate and painful trade effect.

The third is that responses would not necessarily be tit-for-tat, according to all three diplomats. If Mr. Trump orders a 20 percent across-the-board tariff on Europe, that does not mean that Europe must respond with a 20 percent across-the-board tariff on the United States. The E.U. still wants to abide by global trade rules upheld by the World Trade Organization, which could suggest a more surgical approach.

One option on the table is the use of an “anti-coercion instrument,” a relatively new legal framework that would allow the bloc to rapidly target large American service providers — like big technology companies — with tariffs.

In force since 2023, the tool allows the E.U. to use “a wide range of possible countermeasures” like higher customs duties or import limits when another country harms European industry in an attempt to put pressure on the government and bring about political or policy change. The idea is to allow the bloc to respond to manipulative political pressure swiftly and sternly.

The Financial Times initially reported that the commission could use the tool to hit service providers, including large Silicon Valley technology companies, in response to American tariffs. Two of the diplomats confirmed that using the tool was being discussed, though far from a sure plan.

They said that moving forward with the tool might be too drastic of an option because Europe’s ultimate goal is not to inflame an all-out trade war.

For now, it is impossible for Europe to solidify a reaction plan. The simple reason: Nobody knows what Mr. Trump is going to do.

“They want to do a deal — I think they’re very uncertain still about what the true objectives are,” said Jörn Fleck, senior director with the Europe Center at the research group The Atlantic Council.

Also, E.U. leaders have at times struggled to get Washington on the phone. Marco Rubio, the secretary of state, has been invited to meet with foreign ministers but has not done so, though he has had a call with the bloc’s top diplomat, Kaja Kallas. Ms. von der Leyen has not met with Mr. Trump since the inauguration in January.

Even though Mr. Trump has not said what tariffs on Europe would look like, he has repeatedly said he wants Europe to buy more American cars and farm products, in addition to gas.

That has left Europe offering incentives in an effort to fend off the trade war before it begins. Officials have been clear that they are willing — even poised — to buy more American fuel. Officials are already trying to find a way to diversity their energy sources as the continent weans itself off Russian gas.

“We still get a lot of LNG from Russia, and why not replace it by American LNG,” Ms. von der Leyen said in the days after Mr. Trump was elected, referring to liquefied natural gas.

European officials have also said they are likely to buy more American defense products as they ramp up bloc-wide military spending. Higher military expenditures are, in part, a response to Mr. Trump, who has insisted that European nations spend more on NATO.

And when it comes to Greenland — an autonomous territory of Denmark, an E.U. member, that Mr. Trump wants to annex for its strategic importance — Europeans have emphasized that they are open to investing more in the island.

“I totally agree with the Americans that the High North, that the Arctic region, is becoming more and more important when we’re talking about defense and security and deterrence,” Mette Frederiksen, the prime minister of Denmark, said in Brussels this week. “And it is possible to find a way to ensure stronger footprints in Greenland.”

Above all, European leaders have been trying to remind America of how important the relationship between the E.U. and the United States is, both economically and for global peace.

Not only is the E.U., when treated as a bloc, America’s most important trading partner. It is also a major importer of American services, and, as officials have repeatedly emphasized in recent days, European companies employ millions of Americans.

“A lot is at stake for both sides,” Ms. von der Leyen said this week.

But she added that “we will always protect our own interests — however and whenever that is needed.”

Ana Swanson contributed reporting.

A small plane contracted by the Pentagon crashed in the southern Philippines on Thursday, killing all four people aboard, including a member of the U.S. military, officials said.

The plane, a Beechcraft King Air 300, crashed in the municipality of Ampatuan in Maguindanao del Sur Province on the southern island of Mindanao, the Philippine authorities said on Friday. It was on its way from Cebu Province to Cotabato City, the capital of a Muslim autonomous region on Mindanao.

The incident occurred during a “routine mission in support of U.S.-Philippine security cooperation activities,” U.S. Indo-Pacific Command said in a statement on Friday.

“The aircraft was providing intelligence, surveillance and reconnaissance support at the request of our Philippine allies,” the statement said. The names of those killed were being withheld until family members could be notified.

The Philippines is the oldest treaty ally of the United States in Asia. U.S. troops have been deployed for years at a military camp in Mindanao to help train Philippine soldiers fighting Muslim separatist militants. In 2017, U.S. Special Forces assisted the Philippine military as it fought Islamic State-linked militants in the southern city of Marawi.

When President Trump threatened to impose steep tariffs on Mexico, Canada and China, he blamed these three countries for enabling the flow of fentanyl into the United States and fueling what officials have called a national emergency.

President Claudia Sheinbaum of Mexico swiftly pushed back on Mr. Trump’s suggestions that her government colluded with drug traffickers, calling it “slander.” And she also put the blame on the United States, arguing that the fentanyl crisis stemmed from immense domestic demand for drugs, including fentanyl, and the illegal sale of U.S. guns to cartels.

Ms. Sheinbaum announced Monday that she had reached an agreement with Mr. Trump, who agreed to pause the tariffs as she promised to send 10,000 members of the National Guard to the U.S.-Mexico border to stop the trafficking of fentanyl.

But thwarting the transport of the deadly synthetic opioid into the United States poses significant challenges for both the United States and Mexico given the cartels’ immense resources, the ease with which fentanyl is produced and moved and the insatiable demand for narcotics among U.S. consumers, analysts and experts say.

Given these factors, it may be extremely difficult for Mexico to demonstrate that it is meeting Mr. Trump’s terms — particularly within the 30-day window he allotted to delay the imposition of tariffs.

Fighting the cartels is hard, and often futile.

For over a decade, most of Mexico’s efforts to tackle organized crime focused on targeting powerful leaders to weaken their grip on large swaths of territory.

But the strategy backfired. Engaging in direct confrontations and going after senior cartel members led to these groups splintering into smaller, disorganized and violent cells that caused even more bloodshed. While those actions were symbolic and put pressure on the criminal groups, analysts say, the strategy never focused on or intended to thwart the cartels’ production capabilities. Instead, its goal was to stem the violence disrupting communities.

Mexico’s previous president, Andrés Manuel López Obrador, came to office in 2018 promising a new approach: avoiding direct confrontation with the cartels in favor of addressing the root causes of criminality like corruption and poverty.

But his strategy, which he branded with the slogan “hugs, not bullets,” did little to tame the extraordinary levels of violence or diminish the ever-expanding power of cartels that traffic drugs across the U.S. border.

When Ms. Sheinbaum took office in October, she said she would continue Mr. López Obrador’s focus on the social causes of the violence, while also working to lower rates of impunity and build up the national guard. In her first few months, she has taken a tougher line on organized crime, ramping up operations that have led to large seizures of fentanyl and a slew of arrests.

But analysts still question whether this can truly have a big effect.

One of the most prolific producers of fentanyl in Mexico is the Sinaloa Cartel, which traffics most of the fentanyl entering the United States. Given its vast financial, logistical and operational resources, the group has been able dominate production “with an impressive ease,” said Alberto Capella, a security analyst and former police chief of the Mexican states of Quintana Roo and Morelos.

Mr. Capella added that even if Mexican authorities could seize every shipment of fentanyl before reaching the border, the root of the problem would not disappear.

“The problem is not the existence of Mexican cartels; it is the existence of a mass consumption and markets,” said Mr. Capella. “If the mass market of consumers prevails, it will immediately lead to the emergence of suppliers to satisfy this mass consumption, whether it is fentanyl or any other drug,” Mr. Capella added.

Chemicals coming from China are hard to regulate.

Given its robust chemical industry, China is the major supplier of the raw compounds, known as precursors, needed to produce synthetic drugs, including fentanyl and methamphetamines.

As the fentanyl crisis continued to take lives in the United States in recent years, the Biden administration sought more counter narcotics cooperation with President Xi Jinping of China to tackle the issue. Last year, China announced new regulations and tightened controls on the precursor chemicals, including increased government oversight on several chemicals used to make fentanyl.

Fentanyl deaths in the United States did drop in the last year. Yet Mr. Trump still issued a 10 percent tariff on all Chinese products on Tuesday, the result of an executive order issued over the weekend aimed at pressuring Beijing to further crack down on fentanyl and precursor shipments.

But even more regulations may not bring significant results.

Some of the chemicals used to manufacture fentanyl are very common and are used in the production of plastics, perfumes, pharmaceuticals and more, making broad restrictions difficult.

Criminal groups are also now coming up with new methods and risky ways to maintain fentanyl production and potency, and to circumvent regulations.

Sinaloa Cartel members are, for instance, experimenting on animals and people to come up with potent concoctions, including mixing their formulas with substances like animal tranquilizers to keep people hooked.

The group is also luring chemistry students and professors to synthesize the chemical compounds, with the goal of sidestepping the need to import those raw materials from China.

Fentanyl is easy to transport, hard to intercept.

In the past five years, the amount of fentanyl crossing the border has increased tenfold, with Mexico being the source of almost all of the synthetic opioid seized by U.S. law enforcement in recent years.

Fentanyl is a potent and fast-acting drug that is highly addictive. It is 100 times more potent than morphine, which means a small quantity goes a long way: Two milligrams can kill you.

Because the synthetic opioid is so potent, it is shipped in small, compact packages that are easy to transport and hide, making them less detectable and harder to intercept. As opposed to other drugs like cocaine, marijuana and methamphetamine, which are regularly trafficked in tons, fentanyl is moved in kilos.

It takes only a small amount to make hundreds of thousands of laced pills. Even in small quantities, it is extremely profitable, meaning couriers can smuggle small amounts and make a considerable profit by hiding it in their vehicles, under their clothes or in backpacks.

Of the people smuggling synthetic opioids into the United States, most are not undocumented migrants traversing the desert, swimming across the Rio Grande or moving through secret tunnels, as Mr. Trump has suggested.

The largest known group of fentanyl smugglers are Americans coming through legal ports of entry. More than 80 percent of the people sentenced for fentanyl trafficking at the southern border are U.S. citizens, federal data shows.

The New York Times has found that cartels are recruiting thousands of Americans and turning them into fentanyl mules who can easily cross back and forth into the United States and carry the drug mostly in their private cars.

Almost all the fentanyl found at the southern border arrives in cars and just 8 percent of private vehicles that cross are scanned for drugs, according to Customs and Border Protection.

Fentanyl is easy to make; it can be cooked in small kitchens.

Whereas methamphetamine needs large laboratories and specialized equipment to produce, fentanyl can be made in small kitchens and makeshift labs using rudimentary cooking utensils.

New York Times reporters gained access last year to a fentanyl lab in the state of Sinaloa, where there is a turf war underway between rival factions of the Sinaloa cartel. They witnessed firsthand how the deadly opioid was made in a small kitchen using an immersion blender and cooking pans. In one single batch, the cooks were making 10 kilos, an amount that can reap a profit of up to $6.4 million dollars, according to U.S. prosecutors.

Cooks and operatives affiliated with the cartel have revealed in interviews that since the conflict erupted in September, Ms. Sheinbaum has deployed hundreds of soldiers to Culiacán, the capital of Sinaloa, to combat violence and fentanyl production. This escalation has led to increased arrests and the dismantling of laboratories, forcing them to frequently relocate out of fear of detention.

Still, fentanyl is so incredibly profitable that it is just too good to pass on, cooks and senior members of the Sinaloa Cartel have said, making it highly unlikely that they will stop producing what they consider a miracle product.

As one cook said: “This is what makes us rich.”