ESG management is becoming a mainstream trend in corporate management in all industries. In the environmental sector of ESG, there is a global consensus on the need to reduce carbon emissions to fight the climate crisis, and a wide variety of initiatives have been proposed. The Glasgow Financial Alliance for Net Zero (GFANZ) of the United Nations Environment Programme (UNEP) is one such initiative that has formed sector-specific organizations across the financial industry and set out guidelines for action to achieve collective goals. In the insurance sector, the Net-Zero Insurance Alliance (NZIA) was launched. The NZIA started in July 2021 with eight large insurance companies as members. At one point, the number of members reached 30 as more and more insurers realized that ESG management was an essential requirement for corporate sustainability. However, in May 2023, 23 U.S. states warned NZIA member insurers that they would likely violate U.S. antitrust laws if they conducted business under NZIA guidelines. As of February 10, 2024, only 11 companies remained in the alliance. Korean insurers Samsung Fire and Maritime and Shinhan Life have already withdrawn, leaving K.B. Insurance as the only remaining member of the NZIA. This situation involves several complex issues and is more than just a matter of the number of NZIA member companies rising and falling. For example, if an insured seeks fire insurance, can member insurers refuse to underwrite the risk because the insured is a carbon-emitting company? Would an insurance company be sanctioned as a boycott or business entity of illegal cartel conduct under U.S. antitrust law? Will antitrust enforcement extend beyond insurance to banking and asset managers? Is this a political move by the U.S. Republican Party in the run-up to the presidential election or a solid legal judgment? Is it part of a U.S. context that has seen repeated withdrawals from and accessions to the Paris Agreement on Climate Change and anti-ESG legislation on a state-by-state basis?
 There are so many complex factors in these questions that it’s difficult to determine a definitive answer. However, leading global insurance companies see the potential for antitrust violations as a severe legal risk. This article examines the rise and fall of the NZIA, ESG trends and backlash, and the potential for antitrust violations in the insurance business, which is the only financial industry exempt from federal antitrust laws. This is an issue of extraterritorial application of antitrust law, but it also introduces the position of E.U. Competition Law and the TFEU, which are critical of the attitude of the 23 U.S. states. Art.125 Mutual Agreement in the Korean Insurance Business Act and Art.3 Application to Acts Conducted Overseas, Art.56 International Cooperation of the Fair Trade Commission, Art.116 Legitimate Acts under Statutes or Regulations in Korean Monopoly Regulation and Fair Trade Act do not solve the problem.
 The question of whether NZIA members would violate U.S. antitrust laws is currently unanswered. And significant variables such as the outcome of the U.S. presidential election, the policies of the Republican Party, the global trend of pro-ESG, and the possibility of sudden litigation risk should be noted. Whether you win or lose on the merits, antitrust litigation in the U.S. is an arduous process that no business entities wants to go through.