Global fertility rates are experiencing an unprecedented decline, falling below replacement levels in many countries and raising concerns about future population shrinkage. Experts highlight that the drop is not due to a lack of desire for children but is influenced by economic factors, urbanization, and policy legacies such as China's former one-child policy, which has led to demographic imbalances including gender disparities and an aging population. Nations like India, where the population has reached 1.46 billion but fertility rates have declined, face challenges in reversing population decline, as no country has yet successfully done so. Japan's low birthrate, worsened by urbanization, is viewed as a national security concern due to its potential impact on defense and emergency response capabilities. Governments worldwide are increasingly seeking solutions to address falling birthrates amid worries about long-term sustainability and societal survival. The United Nations and various research institutions have emphasized that humanity may begin to shrink several decades earlier than previously expected, prompting debates on whether declining populations might lead to a more sustainable future or pose significant risks.