find someone who will do ti. Generally better to say 'Yes' and then do it your way. If you get it done, they can say little, if you don't they'll can you any way...

Some things have to get a flat 'No, Sir. I cannot do that' but they're relatively rare in my observation and generally, if what you say makes sense, you' ll win the argument.

All of which gets away from the poor Theater Commander who pretty much has to say he can do this thing...