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.
Surface mining. Surface mining techniques are used when a vein of coal or other substance lies so close to the surface that it can be mined with bulldozers, power shovels, and trucks instead of using deep shaft mines, explosive devices, or coal gasification techniques.