Oscilloscopes, spectrum analyzers, and analog signal generators.

They are, to most people, obscure electronic instruments, difficult to use, even hard to pronounce. But they are some of the most highly sought and highly controlled goods in modern warfare, their export limited by the US government because they are crucial to Russia sustaining its war machine. It was these components, authorities say, that were regularly shuttled through a suburban New Hampshire home, a way station on a global smuggling ring that started with unsuspecting American companies and ended in Russia.

A federal indictment unsealed Tuesday illuminates the inner workings of what authorities said was a Russian intelligence network tasked with skirting US sanctions and obtaining Western technology for some of Russia’s premier scientific and military agencies.

“What this indictment shows is that all of the major [Russian] agencies are reliant on a wide range of export-controlled goods inside the United States and their people there tasked with exporting those goods,’’ said James Byrne, a director at the the UK-based defense think tank Royal United Services Institute.

Of the seven people indicted, Alexey Brayman, 35, of Merrimack, N.H., was on the lower rung of this global smuggling ladder, according to authorities. The group served Serniya, which procures high-end Western technology on behalf of the Russian security agency FSB and Rosatom, the state corporation overseeing nuclear energy, according to the indictment.

“We don’t know whether we’ve just discovered the biggest network in existence or if it’s just the tip of the iceberg,’’ said Chris Miller, a professor at the Fletcher School of Law and Diplomacy, who specializes in Russian technology and geopolitics. “But any insight is rare and welcome.’’

Brayman repackaged high-tech components that were shipped to his Merrimack home piecemeal, authorities said, and then sent them to Estonia. There, an FSB agent named Vadim Konoshchenok would ferry the goods across the Russian border, authorities alleged.

Occasionally, Konoshchenok was caught by Estonian border guards, one time red-handed with tens of thousands of rounds of American bullets, including sniper rounds made in Nebraska. Even more worrying to experts were the 35 different types of semiconductors they allegedly found in his car on a smuggling trip in late October.

Sometimes as small as a fingernail, the advanced chips are to modern-day warfare what Kalashnikov rifles were to the Cold War. They are fundamental to modern electronics, found in everything from smartphones to ballistic missiles to fighter jets to tanks. But there are only a few countries that can make advanced chips; the United States is one, Russia is not.

Still, recent reports show that many Russian weapons systems run on advanced chips manufactured in the United States — in some cases, components made within the last year. The missiles that decimated the electrical and water systems in Kyiv on Nov. 23 contained semiconductors from the United States, according to an investigation by Conflict Armament Research, a group in Britain that tracks weapons and ammunition used in wars.

“If an arrest in the States stopped one network, then that actually translates to thousands of components that contribute to hundreds of different weapon platforms that might kill Ukrainians. Even stopping one network may mean that those weapon platforms didn’t get built, or there’s a month delay or two month delay,’’ said Byrne, who authored a separate report from the Royal United Services Institute on the pipeline of Western electronics into Russia. “That can make a world of difference.’’

After the end of the Cold War, the United States loosened its controls on this technology, and the Kremlin’s urgency to learn how to manufacture the chips domestically became less of a priority, experts told the Globe. Russia was able to build stockpiles of semiconductors from the West with relative ease. But as the war in Ukraine has raged on and exhausted that arsenal, Russia has had to find other means to replenish its supply.

“The issue Russia faces at the moment is they have expended huge volumes of equipment. Huge volumes of equipment. They’ve lost so much stuff they need procurement at scale with this loss,’’ said Byrne, who was consulted by authorities on the smuggling case.

But at the heart of the procurement networks are human agents, who are expensive and time-consuming to develop, and, at times, fallible, as the recent indictment revealed. Byrne believes that Brayman, who ran a crafts company with his wife that made decorative lights, is actually “a trained intelligence agent who’s been living as an illegal in the country for a long time.’’

Humans are also fallible, as the recent indictment revealed when a Russian agent — a defendant named Boris Livshits — bought a signal generator from an American company and addressed it to Brayman in July 2022. Authorities installed a tracking device on the item that led them to Brayman’s house in Merrimack, where neighbors said boxes would routinely stack up on the front porch in plain sight.

“Planting someone like him is always really expensive, though, because it requires a huge amount of resources to put these people in place across different countries so that they can act as these nodes in the network when the time comes,’’ Byrne said. “It is a critical weakness to their system.’’

The Kremlin’s war machine has always been dependent on Western technology, materials that the country has struggled to produce itself. In 1963, the KGB established a division called Directorate T — t for technology — that was tasked with acquiring Western electronics. As Silicon Valley emerged as a hotbed for technological innovation, Russia sent some of its best espionage talent to California.

“The San Francisco consulate continues to be staffed with the creme de la creme, even more than Washington,’’ one Russian defector said in a 1981 Newsweek article.

The Kremlin knew that relying on the United States and espionage networks to acquire such technology was an Achilles’ heel for the country. So for years, it tried to kickstart domestic production of the goods, particularly semiconductors. But the effort was always one step behind that of the West and fizzled out as quickly as it began, according to numerous experts.

“You can’t solve this problem by just throwing money at it because it requires research and development talent and against the background of brain drain. They’ll be forever trying to copy, rather than develop,’’ said Maria Shagina, an expert on international sanctions at London’s International Institute for Strategic Studies.

Shagina likened the networks to an octopus: “You cut off one arm and another will grow.’’

Hanna Krueger can be reached at hanna.krueger@globe.com. Follow her on Twitter @hannaskrueger.