A new study warns against oversimplifying the causes of extreme weather. While the Asian monsoon can influence North American climate, researchers found its usual effect is to cool the Pacific Northwest. However, during the 2021 heatwave, a uniquely strong jet stream acted as an "atmospheric waveguide," redirecting the monsoon's energy and amplifying the heat. This shows that a factor's general influence ("can it?") can differ from its role in a specific event ("did it?"), highlighting the need for detailed, case-by-case analysis.