BANGKOK (AP) — New York prosecutors’ decision this week to charge a former assistant to New York’s governor with acting as an illegal agent of the Chinese government has raised concerns about China’s efforts to influence U.S. policy.

Linda Sun has served in multiple positions in New York state government, including deputy chief of staff to Gov. Kathy Hochul. She is accused of pushing Chinese interests at state functions, including allegedly blocking Taiwanese officials from meeting with the governor, in exchange for financial benefits worth millions of dollars.

Sun’s arrest on Tuesday is the latest and perhaps most high-profile in a series of cases pursued in recent years by the U.S. Justice Department to eliminate Beijing’s agents on U.S. soil.

While previous cases involved allegations against suspected Chinese spies who informed on and spied on dissidents critical of the Communist Party, Tuesday’s case appears to indicate how China is trying to directly influence U.S. policy in line with its interests, even at the local level.

WHY STATE LEVEL?

China believes that developing state-level relations with U.S. officials is important and has always done so.

Even as bilateral relations between the U.S. and China have become increasingly strained, the two countries have cultivated broad regional ties since the 2010s, and U.S. governors frequently visit China to strengthen trade and cultural ties.

In recent years, there has been a sharp 180-degree turn as the U.S. government’s relationship with China has become increasingly confrontational, and getting tough on China has become a bipartisan consensus. The White House and Congress are imposing high tariffs on Chinese products and restricting high-tech exports to China.

Some states are even passing laws to actively ban Chinese presence. Georgia, Florida, and Alabama are just a few of the states that have banned Chinese “agents” from buying real estate.

The push for state-level influence “has become increasingly important as federal relations have deteriorated,” said Mareike Ohlberg, a senior fellow in the Indo-Pacific program at the German Marshall Fund of the United States who studies China. “Something is better than nothing.”

HOW DOES BEIJING INFLUENCE COUNTRIES ABROAD?

The Chinese Communist Party has a branch specifically charged with working overseas, called the United Front. Under the control of the United Front are many groups that serve to engage overseas Chinese under the guise of social or industrial groups. Well known among these groups is the All-China Federation of Returned Overseas Chinese, which itself oversees a number of smaller groups.

These groups seek to expand their membership abroad and build connections with the Chinese diaspora. They have branches all over the world, from Africa to Southeast Asia to North America.

Sun was associated with Shi Qianping, who Chinese state media said was a standing committee member of the All-China Federation of Returned Overseas Chinese. Shi also served as head of the U.S. Federation of Chinese-American Entrepreneurs, according to Xinhua.

According to the group, Sun also worked with regional branches of the Returned Overseas Chinese group, such as in Jiangsu province, where Sun was born.

In addition to these groups, concerns are growing about Chinese police stations set up overseas without the knowledge of the countries they operate in. Last year, New York police arrested two men for allegedly setting up a secret police station for a Chinese provincial police agency.

WHAT DOES BEIJING WANT?

Sun’s case, which at first glance might seem like the stuff of a spy movie, showed that China was interested in building influence on a subtle level — for example, by promoting messages that aligned with Beijing’s views.

Prosecutors say Sun urged a Chinese official to discuss a video Hochul recorded while she was vice governor wishing people a happy Lunar New Year. Prosecutors say she specifically prevented Hochul from mentioning human rights issues in China in the video. Sun also allegedly prevented Taiwanese government officials from meeting with top New York state officials. China says Taiwan, a self-governing democracy, is part of its own territory and views any interactions between Taiwanese and other governments as a violation of its claim to sovereignty.

SHOULD COUNTRIES STOP COOPERATION WITH CHINESE PROVINCES?

China often has the ability to set the agenda when it comes to local engagement. “There was a lot of mismatch in terms of resources between the PRC and the U.S.,” Ohlberg said. For example, the city of Shanghai has hundreds of staff dedicated to international engagement, while U.S. states may have only a handful.

“In this case, you need more strategic thinking, more resources and knowledge, and only when you have all that can you make a decision,” she said.