Why it matters: With just weeks to go before the presidential election, the reports from journalist Bob Woodward's new book "War" have raised fresh questions about Trump's ties with leaders of one of the U.S.' greatest geopolitical adversaries.
Driving the news: News of Trump's reported phone calls with Putin have caught the attention of his opponents as a possible violation of the Logan Act, which restricts private citizens from engaging in diplomatic affairs with U.S. rivals.
What exactly did Trump allegedly do?
Woodward reported that -- according to an unidentified Trump aide -- the former president and Putin have had "as many as seven" personal conversations since Trump left office in 2021.
What they're saying: Trump campaign spokesperson Karoline Leavitt told Axios Wednesday that reports of phone calls between Trump and Putin were "unequivocally false" and "completely fabricated."
What is the Logan Act?
The Logan Act prohibits private U.S. citizens from engaging without authorization in diplomacy with foreign governments that are in dispute with the U.S.
State of play: Though the Logan Act was enacted in 1799, the law has rarely been enforced, according to a 2018 report from the Congressional Research Service.
Did Trump violate the Logan Act?
Whether Trump's reported phone calls with Putin violate the Logan Act depends on the content of their conversations, which remains unknown, according to Ku.
Between the lines: However, criticism of the Logan Act as possibly violating the First Amendment means that even if the conversations did violate the law, the former president would still have a "pretty good First Amendment defense if it ever got to court," Ku added.
How has the Logan Act been used?
Although the Logan Act may not be a frequently used legal tool, it's often bandied by politicians and other political groups to take aim at their opponents.
The big picture: The Logan Act has remained a "useful way for people to accuse each other of undermining U.S. foreign policy" because its broad language makes it widely applicable to different correspondences with a foreign government, Ku said.
Has Trump been accused of violating the Logan Act before?
Trump himself was accused of violating the Logan Act in March by hosting a meeting with Hungarian Prime Minister Viktor Orbán at Mar-a-Lago.
The bottom line: While Trump's actions might be "unseemly," the history of the Logan Act and the fact that it's never been legally tested mean that it's not a "meaningful law" that's "likely to ever be used, against Trump or anyone else," Ku said.
Go deeper: Trump has had "as many as seven" phone calls with Putin since leaving office, book claims