WASHINGTON (AP) — In less than two months, President Donald Trump and Defense Secretary Pete Hegseth say the U.S. military has killed 32 people in seven strikes against drug-smuggling vessels in the Caribbean Sea. 

Trump has justified the attacks as a necessary escalation to stem the flow of drugs into the United States. He has asserted the U.S. is engaged in an “armed conflict” with drug cartels, relying on the same legal authority used by the Bush administration when it declared a war on terror after the Sept. 11 attacks.

But as the number of strikes has grown, a debate in Congress has escalated over the limits of the president's power. The attacks have occurred without any legal investigation or a traditional declaration of war from Congress, and some lawmakers have raised questions about the lack of hard evidence to justify the killings. 

Meanwhile, an unusual naval buildup off South America has stoked fears of invasion in Venezuela and speculation that Trump could try to topple President Nicolás Maduro, who faces charges of narcoterrorism in the U.S.

Here is a timeline of the U.S. military actions and the concerns among some lawmakers:

Jan. 20

Trump signs an executive order on his first day back in the White House that paves the way for criminal organizations and drug cartels to be named “foreign terrorist organizations.” They include Tren de Aragua, a Venezuelan street gang.

The U.S. intelligence community has disputed Trump’s central claim that Maduro’s administration is working with Tren de Aragua and orchestrating drug trafficking and illegal immigration into the U.S.

Feb. 20

The Trump administration formally designates eight Latin American crime organizations as foreign terrorist organizations.

The label is normally reserved for groups like al-Qaida or the Islamic State that use violence for political ends — not for profit-focused crime rings.

Aug. 19 

U.S. officials confirm the military deployed three Aegis guided-missile destroyers to the waters off Venezuela as part of Trump's effort to combat threats from Latin American drug cartels.

The naval force in the Caribbean grew within weeks to include three amphibious assault ships and two other U.S. Navy vessels, about 6,000 sailors and Marines in total. The amphibious assault ships have a variety of aircraft on board, and the U.S. deployed F-35 fighter jets to Puerto Rico in September.

A Navy submarine also is operating off South America and is capable of carrying and launching cruise missiles.

Sept. 2

The U.S. carries out its first strike against what Trump says was a drug-carrying vessel that departed from Venezuela and was operated by Tren de Aragua.

Trump says 11 people were killed and posts a short video clip of a small vessel appearing to explode in flames. The video does not show any large or clear stashes of drugs inside the boat. 

Sept. 10 

In a letter to the White House, Sen. Tim Kaine of Virginia and two dozen other Democratic senators say the Trump administration has provided “no legitimate legal justification” for the strike.

Sen. Jack Reed of Rhode Island, the top Democrat on the Senate Armed Services Committee, says in a floor speech that week that the U.S. military is not “empowered to hunt down suspected criminals and kill them without trial.”

Sept. 11

In Venezuela, Interior Minister Diosdado Cabello accuses the U.S. government of murder, while questioning how the people on board the targeted vessel were linked to the gang.

“And how did they identify them as members of the Tren de Aragua? Did they have, I don’t know, a chip? Did they have a QR code and (the U.S. military) read it from above in the dark?” Cabello said. “They openly confessed to murdering 11 people.”

Sept. 15

The U.S. military carries out its second strike against an alleged drug boat, killing three people. 

Asked what proof the U.S. has that the vessel was carrying drugs, Trump told reporters: “We have proof. All you have to do is look at the cargo that was spattered all over the ocean — big bags of cocaine and and fentanyl all over the place.”

Sept. 19 

Trump says the U.S. military carried out its third fatal strike against an alleged drug smuggling vessel. The president says the attack killed three people and that intelligence “confirmed the vessel was trafficking illicit narcotics.” 

Several senators and human rights groups continue to question the legality of the strikes, describing them as a potential overreach of executive authority.

Oct. 2

Trump declares drug cartels to be unlawful combatants and says the U.S. is now in an “armed conflict” with them, according to a Trump administration memo obtained by The Associated Press. 

The memo appears to represent an extraordinary assertion of presidential war powers, with Trump effectively declaring that trafficking of drugs into the U.S. amounts to armed conflict requiring the use of military force.

The memo drew criticism from some lawmakers, including Republican Sen. Rand Paul of Kentucky. He said only Congress has the authority to declare war and characterized the memo as “a way to pretend like” the administration is notifying lawmakers with a justification for the strikes.

Oct. 3

Hegseth says he ordered a fourth strike on a small boat he accuses of carrying drugs in the waters off Venezuela. He says the strike killed four men but offers no details on who they were or what group they belonged to. 

Trump says in his own social media post that the boat was “loaded with enough drugs to kill 25 TO 50 THOUSAND PEOPLE” and implied it was “entering American Territory” while off the coast of Venezuela.

Oct. 8

Senate Republicans vote down legislation that would have required the president to seek authorization from Congress before further military strikes on the cartels. 

The vote fell mostly along party lines, 48-51, with two Republicans, Paul and Sen. Lisa Murkowski of Alaska, voting in favor and Democratic Sen. John Fetterman of Pennsylvania voting against.

Oct. 14

Trump announces the fifth strike against a small boat accused of carrying drugs, saying it killed six people. The president says “intelligence” confirmed the vessel was trafficking narcotics, associated with “narcoterrorist networks” and on a known drug trafficking route.

Oct. 15

Trump confirms he has authorized the CIA to conduct covert operations inside Venezuela and says he was weighing carrying out land operations on the country.

The president says the administration “is looking at land” as it considers further strikes in the region. He declines to say whether the CIA has authority to take action against Maduro.

Oct. 16

The Navy admiral who oversees military operations in the region says he will retire in December. 

Adm. Alvin Holsey became the leader of U.S. Southern Command only last November, overseeing an area that encompasses the Caribbean Sea and waters off South America. These types of postings typically last between three and four years.

Oct. 16

Trump says the U.S. struck a sixth suspected drug-carrying vessel in the Caribbean, killing two people and leaving two survivors who were on the semi-submersible craft. 

The president later says the survivors would be sent to Ecuador and Colombia, their home countries, “for detention and prosecution.” Repatriation avoided questions about what their legal status would have been in the U.S. justice system. 

Oct. 17 

The U.S. military attacks a seventh vessel that Hegseth says was carrying “substantial amounts of narcotics” and associated with a Colombian rebel group, the National Liberation Army, or ELN. He says the strike killed all three “terrorists” on board. 

When Hegseth announces the strike on Oct. 19, he does not provide any evidence for his assertions but shares a brief video clip of a boat engulfed in flames. 

Oct. 20

Rep. Adam Smith, a ranking Democrat on the House Armed Services Committee, calls for a hearing on the boat strikes. 

“Never before in my over 20 years on the committee can I recall seeing a combatant commander leave their post this early and amid such turmoil," Smith said in a statement of Holsey's impending departure. “I have also never seen such a staggering lack of transparency on behalf of an Administration and the Department to meaningfully inform Congress on the use of lethal military force.”

Oct. 21

A team of independent experts commissioned by the United Nations’ Human Rights Council blasted the “covert actions and threats” the U.S. is using against Venezuela, saying that the attacks are taking place without proper legal basis.

“These actions also violate the fundamental international obligations not to intervene in the domestic affairs or threaten to use armed force against another country,” the experts said in a statement. “These moves are an extremely dangerous escalation with grave implications for peace and security in the Caribbean region.”

The statement said that experts have relayed their concerns to U.S. officials.

– Ben Finley and Konstantin Toropin, The Associated Press