You must have heard of a bad decision. One can argue whether it is totally bad or just worked out badly. Either way, the word bad applies. Sometimes they may look like bad results from ideas we still think are good at the time.
Many wars are started to take over somebody else’s stuff, or to stop somebody from taking over stuff. Wars are fought for ideas, destroying people for the sake of an idea.
War is a good example of misguided intentions that went badly. I know World War I was a little bit of time ago, but the example is still good for today. World War I started when Archduke Franz Ferdinand of Austria and his wife were assassinated as they rode in an open carriage by a group who wanted to split away from Serbia and form their own country. Because several countries had agreements to help each other, fighting started and spread across all of Europe. Hundreds of thousands of troops faced each other in trench warfare, attacking and blowing up each other, but neither side really gained anything in land or victory for years.
In the first December of the war, in 1914, a truce was called to halt all fighting for the one day to observe Christmas. One day. On that day each side of combatants sang songs that their enemies could hear in the close distances between their lines. After deciding it was not a trick, both sides ate and drank, played soccer, and sang songs together. Peace for Christmas.
The next morning no one wanted to start fighting again. The military commanders had to threaten their troops to force them to begin killing again. Did anyone want to kill, die, or become maimed? H*!! No! But these citizens, who had been conscripted to fight in the war, could only fight or be shot for the crime of not supporting what the government wanted out of them.
So now we have more choice. That choice can be rallied to a cause by others. What is our own life to be used for, or rather what can it provide? To sacrifice oneself for the goals of some large central authority? There may be a good compelling reason to choose that, or it may be giving someone else something you may want, your life. It really pays to know your own mind, and choose wisely.