Escalating geopolitical tensions between the U.S. and Iran have led to significant declines in Asian stock markets. On Monday, the South Korean KOSPI index plummeted 6.49%, closing at 5,405.75, a drop of 375.45 points. Similarly, Japan's Nikkei 225 index fell 3.48%, ending the day at 51,515.49, down 1,857.04 points. These declines reflect heightened market fears amid the ongoing geopolitical uncertainties.