What was Aragorn thinking?

So I’m reading Return of the King for the first time (holy shit!!!) and Aragorn has just looked into the stone and shown Sauron the sword, which achieves… making Sauron more likely to attack quicker? So now he’s gotta go through this super dangerous path because he needs to get to Minas Tirith in time?

I don’t wanna get spoiled so I probably won’t read the replies, and I’m also sure I’m either wrong and stupid or just haven’t heard the answer yet, but this just seems silly.