Although many studies take the event study and fuzzy set approach, there is a lack of studies on the impact of international conflict on different sectors within a country. This study uses this approach to calculate abnormal return and cumulative abnormal return to investigate the impact of the Russia-Ukraine war on the U.S. Stock Market of 20 representative companies of 10 U.S. sectors. Covering a 10-day timeframe before and 10-day window following the start of the war which was on 24 February, 2022, and the estimation window is set to 300 days. The research shows that the Russia-Ukraine war has a varied influence on each of the ten industries because of the U.S. sanctions against Russia, the companies in fast-moving consumer goods sector, healthcare sector, consumer discretionary sector, industries sector and materials sector are adversely affected, but energy sector, information technology sector, communication service sector and real estate sector are not affected by the war. Unlike others, the financial sector is most adversely affected.