The countries that invest the most in influencing the U.S. are largely America's closest allies, according to data, at a time when international lobbying is under increased scrutiny.

An analysis of foreign lobbying last year through the Foreign Agents Registration Act, or FARA, compiled by the nonprofit watchdog group OpenSecrets.org shows that some of the countries Americans most revere are also those that invest the most money in shaping U.S. policy.

Many of those high spenders are America's closest allies, beginning with South Korea and Japan and including Canada, Germany and the United Arab Emirates. China – considered a growing rival to the U.S. on the world stage – ranks eighth among top lobbying spenders.

Some countries may target only members of the U.S. Congress to support a specific piece of legislation, such as the Partner with Korea Act currently before lawmakers that last year accounted for a large portion of the $62 million that Seoul and South Korean companies invested. Other countries might try to shape the way Americans perceive their country, such as South Africa, whose $7 million in lobbying in 2017 was largely in support of the country's tourism, or Russia, whose state-sponsored media service RIA Novosti spent more than $100,000 in the U.S. in 2017.

Some countries, particularly Russia, China and Iran, may believe their money is better spent on covert activity rather than publicly trying to shape American debates.

"FARA is only the tip of the iceberg. They have many other ways of influencing attitudes ... in the U.S.," says James Thurber, a professor at American University and co-author of the book, "Congress and Diaspora Politics: The Influence of Ethnic and Foreign Lobbying." "It's a question of how transparent it is in terms of the investment people are making."

Foreign entities face sharp penalties for putting money toward shaping U.S. elections. Their ability to invest in changing American policies is tightly regulated, more so than restrictions on employing U.S.-based corporations to operate in a particular country's interests.

The trial tied to Paul Manafort's overseas connections while serving as campaign manager for President Donald Trump's candidacy has reportedly contributed to a widespread panic among some foreign governments and corporations. Sen. Chuck Grassley, the Iowa Republican, has proposed new legislation that would tighten the FARA rules and make it more clear who may and may not pay to influence how Americans think.

"There's a lot of gambling going on, as they say in 'Casablanca.' And some people are not registering," Thurber says.

A breakdown of the OpenSecrets.org data also reveals how different countries wield their influence, even among America's top allies. The spenders in the top two countries – South Korea and Japan – give different amounts to government and nongovernmental organizations.. South Korea's government, for example, spent $52 million last year while nongovernmental spending totaled $10 million. In Japan, its government spent $6 million while nongovernmental spending was almost $33 million.

The outcomes are not necessarily different. The Japan External Trade Organization, which lobbies on behalf of Japanese companies, is an NGO even though it receives a large amount of its funding from Tokyo. The South Korean government has a culture of more directly supporting its private companies, experts say.

Other countries, such as Saudi Arabia and Israel, have an extensive history of promoting their own cultures while also lobbying for greater U.S. military support, including weapons sales.

"It's not surprising that the countries with which we have the thickest relationships – whether it's in the economic sphere, or in the military procurement sphere – are the ones that are going to be spending the most money on lobbying," says Richard Pildes, a professor of constitutional law at New York University's School of Law. "Countries certainly try to influence the general perception of themselves in the world in a whole variety of ways."

"Scandal brings change," Thurber says. "We're going to see a lot of reforms with respect to FARA coming up."

Some of the countries that Americans consider the most powerful and influential don't break the top 30 for lobbying dollars. Russia, for example, is ranked No. 2 in the 2018 Best Countries power ranking , yet it is 31st among FARA spenders, investing only $1.3 million. Iran, which Americans consider the 13th most powerful country, is ranked 42nd for FARA spending. China was the most powerful country in the eyes of Americans that also dedicated significant amounts of money to overt lobbying, ranking first on that list.