It's not really that insane. Don't overreact to Trump stuff - it leads you to make bad decisions and assumptions.

This archaic and formal "I do declare war upon theee" is not flexible enough for the modern world and so we have found, perhaps an unhappy middle ground where the President can indeed take military action, for a limited period of time (60 days) without congressional authorization. The President is the civilian commander of the military and regardless of whether it is a Democrat or Republican we, like in other cases, give the President the discretion to make these choices. You may not like their exercise of power, but it is legal, Constitutional, and intentional and even if it is Donald Trump (much to my displeasure) we as a society trust him and his office to use this power responsibly and for the good of the American people. Even in the case of Iran and Venezuela, frankly, I think he has used power responsibly (if less effective than it should be) and for the good of the American people. We can't have a nuclear Iran in the Middle East, nor can we or should we accept thugs like Maduro running a country into the ground and causing mass migration to the US and causing problems here and breaking our laws.

There are folks in the cabinet that can take action, or resign, &c., but as the Executive the president selects his cabinet and they serve at his pleasure, once they are confirmed by the Senate. This is true for all presidents and will continue to be so for the foreseeable future.

I think sometimes we forget, these are just people. We give them broad authority and they get to, by virtue of being elected, exercise that power as they see fit though ideally if or when a law is broken we deal with it through the judicial system.