be a double-edged sword
To be something that can be both beneficial and problematic. Going back to school was a double-edged sword for Pam. On the one hand, it widened her career prospects, but, on the other hand, she was in a lot of debt when she graduated.
be a double-edged weapon
To be something that can be both beneficial and problematic. Going back to school was a double-edged weapon for Pam. On the one hand, it widened her career prospects, but, on the other hand, she was in a lot of debt when she graduated.