A Manhattan federal jury on Wednesday convicted Russian arms trader Viktor Bout of four counts of conspiracy to sell antiaircraft weapons and other arms to purported Colombian rebels to kill Americans. He faces a term of 25 years to life in prison.

The verdict closed the door on a five-year-old sting operation — led by the Drug Enforcement Administration and spanning three continents — that lured Bout out of Russia to a Bangkok hotel where Thai police arrested him in March 2008 as he tried to close a deal with federal informants. He was sent to New York in October 2010, after a lengthy extradition battle that heightened tensions between the United States and Russia.

The jury convicted Bout of all four charges, including conspiracy to kill Americans, conspiracy to kill U.S. government officers and employees, conspiracy to acquire and use antiaircraft missiles, and conspiracy to provide material support or resources to a designated foreign terrorist organization. District Judge Shira Scheindlin scheduled a sentencing hearing for Feb. 8.

“With today’s swift verdict, justice has been done and a very dangerous man will be behind bars,” Preet Bharara, the U.S. attorney for the Southern District of New York, said in a statement. “As the evidence at trial showed, Viktor Bout was ready to sell a weapons arsenal that would be the envy of some small countries. He aimed to sell those weapons to terrorists for the purpose of killing Americans.”

Bout’s attorney, Albert Dayan, said that he would appeal the verdict and that his client had been “wrongfully accused” of a crime. “The jury has spoken, but its position is still not correct. This is not the end,” he said. During the trial, Dayan argued that his client intended to sell cargo planes, not arms.

Starting in late 2006 or early 2007, the DEA paid two federal informants to initiate the purchase of 100 surface-to-air missiles, 20,000 AK-47 rifles, 20,000 fragment grenades, 740 mortars, 350 sniper rifles, five tons of C-4 explosives and 10 million rounds of ammunition on behalf of the Revolutionary Armed Forces of Colombia. They persuaded Andrew Smulian, a longtime associate of Bout’s, to serve as a go-between. Smulian, who has pleaded guilty for his role in the scheme, agreed to cooperate with the prosecution as part of a plea agreement that could lessen his jail time.

Russia has insisted that the United States was pursuing Bout for political reasons and that there was no evidence that he had broken any laws.

Speaking to reporters after the verdict, Russia’s vice consul in New York, Alexander Otchaynov, expressed concern about the “severe conditions” of Bout’s confinement and said the government would continue to provide assistance to his family. But he declined to comment on the substance of the verdict, saying, “There is no official position as to whether it was fair or not.”

Bout, a former Soviet military adviser in Africa, left the military as the Soviet Union collapsed and built an air freight empire in the 1990s, using surplus Soviet-era cargo planes to transport weapons to groups in Angola, Liberia and other conflict zones. He later expanded his operations to Latin America, the Middle East and Asia, according to arms-control experts.

Kathi Austin, executive director of the Conflict Awareness Project, who has tracked Bout’s activities, said the “prosecution’s case was very strong.” But she expressed frustration that it “had taken a sting operation to bring him to justice” when the international community has “had the evidence against him for 15 years.”