Why, after the disasters of Iraq and Afghanistan, would America contemplate sending ground troops into the Middle East again?

This is what the U.S. does. We are fundamentally a war machine. Presidents boast of "no wars" in their candidacies, but we need ongoing war to survive and feed the defense industry. Sometimes that only involves selling weapons to other nations (like Israel), but sometimes it involves being directly involved. Thinking "it will be different this time" (despite the fact that Iran is a much more formidable enemy than Iraq and Afghanistan ever were) is also a key part of never learning from history, something we're great at in this country.