When in 1939 war did break out between Germany on the one hand, and Britain and France on the other, President Franklin D. Roosevelt dutifully invoked the Neutrality Acts. However, he believed that this was a fundamentally different war from World War I.
Another advanced coal technology is coal gasification, a process in which coal is converted to a gas (called syngas) before it is burned, making it easier to separate CO2 as a relatively pure gas before power is generated.
Coal is a fossil fuel that is burned as an energy source, which results in emissions such as carbon dioxide, nitrogen, and sulfur. Coal use is associated with waste products both from the mining process to acquire the coal and also from the actual use of coal itself. Hydroelectric energy does not involve waste, but does pose potential problems to waterways.