What were some historical reasons for the invention of pad thai?
The dish was invented in part to help Thailand develop a national identity, and also to promote consumption of noodles to alleviate rice shortages during world war 2.
Instruction: What were some historical reasons for the invention of pad thai?
Context: 
Response: The dish was invented in part to help Thailand develop a national identity, and also to promote consumption of noodles to alleviate rice shortages during world war 2.