>Drop bombs on the Panama Canal and open it up as a natural waterway.
Won't work.
https://yourpanama.com/panama-canal
Not commonly known is the fact that the two oceans have different sea levels, and different levels of high tide. At the entrance to the Panama Canal, the Pacific Ocean can rise as much as 20 feet, but 45 miles away, the difference between high tide and low in the Atlantic is just three feet.