The long-term effects of the Treaty of Trianon (1920) on Hungary were profound and lasting. The treaty resulted in Hungary losing approximately two-thirds of its territory, including significant lands now part of Romania, Slovakia, and Serbia. This territorial loss led to a significant reduction in Hungary's population and economic resources. The treaty also fostered a sense of national trauma and resentment among Hungarians, serving as a rallying point for nationalist sentiments. These factors contributed to political instability in Hungary over the subsequent decades and played a role in the rise of revisionist movements that sought to reclaim lost territories.