This is not the Wehrmacht in 1940. Avoiding or deterring conventional conflict while pursuing security objectives in your region through propaganda, psychological warfare, and proxy operations isn’t the path to dominating the Middle East, much less becoming the greatest threat to the United States.
If you wanted to posit any Middle Eastern power as being the United States’ greatest adversary, you’d have to portray it as a country that could at least dominate its region. From well before the Carter Doctrine, U.S. defense planners have worried that a hegemon in the Middle East would have outsized influence over oil markets and could wreak havoc on the world price for oil.
Iran has no shot at dominating the Middle East because its outdated and under-maintained armor, its towed artillery, and its lack of experience with offensive combined arms preclude it. Were Iran crazy enough to try to invade a neighbor, stand-off air power could destroy the attacking force without much struggle.
These massive conventional military weaknesses — which are not fixable in the policy-relevant future — preclude Iran from trying to dominate the region. And an Iran that cannot dominate its region cannot constitute the biggest threat to the United States.
Iran does, of course, have a vehemently anti-American ideology, and does support an array of proxies across the region that stymie U.S. objectives. In that sense, dotting the region with defenseless U.S. deployments that do not contribute to achievable military objectives, serving only as triggers for war with Iran and facilitators for Israeli strikes into Syria, seems foolhardy.
The closer the United States gets to Iran, the more Iran can hurt Americans. Iraq was a trivial threat to the United States until we invaded it, which made it into a much bigger problem. Bashing a hornet’s nest or dancing around a pit of quicksand pose real dangers, but as in those cases, the best option vis-à-vis Iran is to simply stay away.
The best defense that can be mounted of Vice President Harris in this context is that she seemed to be groping around for an answer with the least political downside and the least offense to the foreign policy Blob, and she probably found it. The problem is that she is wrong on the substance. Should her extemporaneous remark influence her policy, it could push the United States further down the road to ruin in the Middle East.