You mean like Dresden? Nagasaki? Hiroshima?
1) War crimes are tried by the victors
2) The Laws of War asks for restraint; however, the law also recognizes all out war and that there WILL be civilian casualties and authorize exceptions.
For example targeting of churches is prohibited by the laws of war - however, if the enemy sets up a sniper in the bell tower then taking out the entire church is authorized and considered a practical application of force since the enemy violated the principal first. In the case of city destructions - if (as with Dresden - factories and Nagasaki - naval port) there is a military reason to do so then it is allowable.
In the case of Wuhan -the biological factory infrastructure; in the case of the Dam - electrical power and downstream bridges, and naval ports; Beijing - command and control infrastructure and major military bases.
Not saying it’s the first step you take; however, in war you assess the field and play to win with the minimal effort and loss of your own forces first. Hard decisions all around - but it isn’t beyond the realm of possibilities.