Why did World War II require the rapid construction of many airfields and airstrips?

During World War II, the rapid construction of numerous airfields and airstrips was necessitated by the newfound strategic and tactical importance of air power. As military operations expanded across vast theaters, the ability to project force from the air became a decisive factor in the conflict.1

Military engineers were tasked with building these facilities under extreme pressure, often while under direct enemy fire, to ensure that aircraft could support ground troops, conduct reconnaissance, and maintain air superiority. This requirement was part of a broader shift in military engineering that demanded solutions on a scale and of a character not previously experienced in warfare. The necessity for these airstrips was driven by the need to sustain continuous operations, as air forces required a dense network of bases to effectively engage in both tactical support and strategic missions.12