The US airline industry faced many challenges in the 2000s including financial troubles after 9/11, lower demand during recessions, seasonal fluctuations, increasing fuel costs and security regulations, labor issues, and more competition from low-cost carriers. Regional airlines faced additional problems of dependence on major partners and greater impact from weather. SkyWest was a leading regional airline that partnered with Delta and United, pursuing strategies like geographic expansion and diversifying partnerships to manage risks.