Following a chaotic hearing at Wilmington, Delaware, on Wednesday that saw Hunter Biden’s plea deal delayed, it has become clear that the first son faces a real threat from prosecutors should they choose to charge him with violating the Foreign Agents Registration Act. 

Mr. Biden fils, a lawyer, has acknowledged making millions of dollars working on behalf of clients in Ukraine, Communist China, and other countries who hoped his family name would further their interests in America. He now faces potential prosecution for not registering as a foreign agent as part of his work.

Passed in 1938, FARA governs when and how lobbyists and activists must register with the federal government if they are advancing the interests of a foreign government, business entity, or person. Concerns about foreign influence in America have abounded since the nation’s inception, but the federal government did not take serious steps to regulate such lobbying practices until the early 20th century. 

Shortly after America entered World War I, two pieces of legislation were introduced in the House that were aimed at curtailing Americans’ ability to create propaganda that would have supported the Central Power — the enemy wartime alliance composed of Germany, Austria-Hungary, Bulgaria, and the Ottoman Empire. Although the measures were never passed by Congress, they became the basis for what would become FARA. 

In 1934, the House Special Committee on Un-American Activities recommended to Congress that legislation be adopted to restrict citizens’ ability to advocate for foreign powers. These recommendations were borne of the rise of the Nazi Party in 1930s Germany and covert Nazi efforts to turn American opinion in their favor. 

After years of considering such legislation, President Roosevelt finally signed the law in 1938, which required citizens who did advocate for foreign powers or engage in what authorities viewed as propagandistic activities to register with the government. Because of the First Amendment, the government could not simply ban such advocacy. 

Since the law’s enactment, FARA has been updated by Congress twice, in 1966 and 1995. In both cases, the statute was tailored to include lobbying for foreign governments, businesses, and individuals as a practice that must be reported to the government. 

The 1966 revision, which struck the creation of propaganda for foreign powers as an activity that required registration, created a narrower FARA that left little room for prosecutors to go after propagandists. As a result, only seven charges of violating FARA were brought between 1966 and 2015. 

The Department of Justice has only recently been enforcing FARA more aggressively, and those enforcement efforts have been shaky.  One of President Obama’s White House counsels, Gregory Craig, was indicted in 2019 for allegedly violating FARA after lawyers from Special Counsel Robert Mueller’s office discovered work Mr. Craig had done for the Ukrainian government in 2012. Mr. Craig, one of Washington’s most powerful lawyers, went to court and won acquittal. 

A deputy finance chairman of the Republican National Committee, Elliot Broidy, pleaded guilty to violating FARA in 2020 after doing work on behalf of the Malaysian and Chinese governments. One day before he left the White House, President Trump pardoned Mr. Broidy. 

Mr. Trump’s 2016 campaign chairman, Paul Manafort, was convicted of violating FARA in 2017. The charges stemmed from work Mr. Manafort had done as an unregistered lobbyist — coincidentally, with Mr. Craig — on behalf of the Ukrainian government. He was also indicted for lying to investigators about his work. After spending nearly two years in a federal penitentiary and months in home confinement due to the Covid pandemic, Mr. Manafort was pardoned by Mr. Trump in December 2020. 

The potential case against Mr. Biden came to the fore on Wednesday when the presiding judge in his plea agreement case, Maryellen Noreika, explicitly asked lawyers if their deal had precluded Mr. Biden from ever being prosecuted under FARA. 

“There are references to foreign companies, for example, in the facts section,” Judge Noreika said during the hearing, referring to the plea agreement that disclosed some of the foreign lobbying Mr. Biden allegedly did on behalf of business interests. “Could the government bring a charge under the Foreign Agents Registration Act?” she asked. 

Prosecutors said they could bring charges, while Mr. Biden’s attorneys said they “didn’t agree” with that characterization of the plea deal. This led Judge Noreika to recess the hearing so lawyers could come to an agreement, which they were unable to do. 

After the plea deal fell apart, Mr. Biden pleaded guilty to two misdemeanor charges of tax evasion as a formality. His lawyers and prosecutors said they will figure out the immunity details in the coming days.