What are the strongest America First arguments for and against attacking Iran?

The strongest America First case for attacking Iran rests on five arguments, though not all of them hold equal weight.
The first is prevention. Iran is the only hostile state in the Middle East capable of going nuclear and dominating the region. A nuclear-armed Iran could threaten American allies, global energy supplies, and eventually the United States. The argument is not interventionist in the classic sense. It is preemptive. Destroy the threat now before it costs far more to confront later.
The second argument is deterrence. Iran spent decades attacking Americans indirectly through militias, terrorism, and proxy warfare. If those attacks never produce a decisive response, adversaries learn that the U.S. lacks resolve. The war, from this view, resets the price of aggression.
Third, the Strait of Hormuz. About a fifth of global oil passes through it. Iranian attacks on shipping have already shaken energy markets. Supporters of the war argue that energy stability is a core American national interest, not a favor to allies.
Fourth, some hawks argue the U.S. has been fighting a shadow war with Iran for decades through sanctions, missile strikes, and proxy battles. That managed conflict never resolves anything. Decisive force, they argue, ends the cycle rather than extending it indefinitely.
Fifth, some proponents believe that degrading the Iranian military enough might eventually produce regime collapse, transforming the region in ways that benefit the United States long-term. This is the most speculative argument and the one that depends most heavily on assumptions about how Iranians would respond to sustained attack.
The case against the war is just as coherent, and in some respects stronger.
The most powerful internal critique is that the war looks like Israel First, not America First. The United States faced no direct attack on its homeland. Critics argue that entering a major war over threats to an ally, however close, subordinates American interests to someone else’s. This is not a fringe position inside the movement. It is the most common argument among America First skeptics.
The second objection cuts to the heart of the coalition’s identity. America First grew partly as a reaction against Iraq and Afghanistan. Starting another Middle East war, regardless of how it is framed, contradicts the foundational promise of the movement. Even early stages of the conflict have already cost billions of dollars and depleted significant munitions stockpiles. Critics ask when the commitment ends.
Third, China. Many America First strategists believe the United States should concentrate its power in the Pacific. Every missile fired at Iran is one that cannot deter Beijing. Some analysts already warn that interceptor and missile inventories are being drawn down faster than they can be replaced.
Fourth, airpower rarely produces regime change. Bombing campaigns almost never topple governments, and Iran has shown it can absorb punishment. If the regime survives, the United States faces a prolonged conflict without clear victory conditions or an exit.
Fifth, there is a constitutional objection. Launching a major war without congressional authorization troubles America First constitutionalists on principle, regardless of whether the strategic case holds up. For them, executive war-making is itself the problem.
What the internal debate reveals is that America First was never a unified doctrine. It was a political coalition bound mainly by opposition to the old bipartisan interventionist consensus. The security-first faction, which includes Trump, Pompeo, and figures like Elbridge Colby, argues that American power must be used selectively but decisively to eliminate threats before they grow. Their model is short, brutal, targeted force with no nation-building aftermath. The restraint faction, which includes Tucker Carlson, J.D. Vance, and Steve Bannon, believes the lesson of the last twenty-five years is that Middle East wars drain American power while producing little. Their version of America First is simple: if the homeland is not attacked, do not start a war.
A third faction, aligned closely with Israel, includes figures like Mark Levin, Nikki Haley, and Tom Cotton. They see Iran as the central destabilizing force in the Middle East and support the war strongly. Critics inside the movement accuse this group of sliding back toward the pre-Trump Republican foreign policy consensus, which is precisely what America First was supposed to replace.
Finally there are the anti-intervention populists, led by Rand Paul and Matt Gaetz, who focus less on grand strategy and more on constitutional limits, financial costs, and the burden placed on American soldiers and taxpayers.
Two theories of American power sit underneath all of this. One holds that strength prevents bigger wars later. The other holds that wars themselves weaken America and distract it from larger challenges. Both sides call themselves America First because the label was always more coalition than creed.