Jonah’s actions directly cause the Assyrian conquest of Israel.
Because Jonah is a prophetic book, which is placed after the historical books, most readers don’t realize that this is the first chronological appearance of Assyria. At this point in time, Assyria was not The Empire, but was governed by a series of weak kings who weren’t very powerful. It wasn’t until Tiglath-pileser that Assyria became feared the world over as a brutal expansionist power, and historically he took power some time after this. Moreover, he was a usurper. Could it be that after the Ninevites repented and served God, a reactionary faction who hated this garnered enough resentment to overthrow the king and place Tiglath-pileser on the throne, who went to conquer Israel, a minor kingdom few had then heard of, as an act of revenge? This raises the question of just how far Israel must have fallen by Jonah’s time if this was how God chose to teach them a lesson.The creature that swallowed Jonah was a sperm whale.
While the Bible said that Jonah was swallowed by a great fish, the Hebrews at the time didn't know the difference between a fish and a whale. Sperm whales have the largest digestive tract than any other marine mammal (which makes sense, since they're the only known predator of the giant squid), and they do live in the Levantine Sea. They're found in the deep depths, but like all whales, they do have to surface to breathe.