The United States is rapidly heading down the path of confrontation with a rogue-state adversary, a potential foe that has proved rational yet ruthless in pursuit of its interests, including the aggressive development of its nuclear programme and associated military capabilities. The rogue state this description best fits, however, may not be North Korea, but Iran.
Although the slow-motion crisis involving North Korea's atomic and missile programmes is undoubtedly perilous, it still seems likely that the logic of nuclear deterrence will promote a degree of caution on all sides. In the Middle East, however, the Trump administration is barrelling towards a potential conflict with Iran, one that the White House has shown little capacity to handle thus far.
That looming confrontation is being driven by three powerful factors that are now converging. First is the rapidly approaching endgame of the struggle against the Islamic State in Iraq and Syria (ISIS). The defeat of that terrorist army is removing a point of tacit cooperation between the US and Iran while sharpening the regional competition between them. Washington and Teheran are gearing up for an intense political struggle for influence with the government of Iraq. The potential for violence between any US troops that remain in Iraq and the Iranian-backed Shi'ite militias that strenuously oppose such a presence will be omnipresent.
In Syria, US and Iranian-backed forces are also coming into closer proximity in and around the few areas ISIS still holds. The middle Euphrates River Valley has already seen clashes between the US military and Iranian-backed militias operating in support of the Assad regime. As the vice closes around the militant group, and its enemies strive to stake out their spheres of influence in a post-ISIS Syria, the potential for violence will intensify.
The second factor leading towards a new crisis is the Trump administration's determination to push back against Iran's pernicious influence throughout the Middle East. By the close of Mr Barack Obama's presidency, there was a widespread sense in Washington - and much of the Middle East - that Iran was ascendant, and that it had exploited Mr Obama's war-weariness and his desire to reach the nuclear deal with Teheran to push its influence from South Asia across the Middle East.
In reality, Iran's interest is more intense, and its influence far more pervasive, in Syria, Lebanon and Iraq - which constitute something close to vital strategic interests - than it is in a secondary theatre such as Yemen. But the reality of expanded Iranian sway in the region - and the alarm this has provoked among US partners - is incontestable. Add to this the understandable resentment of Trump administration officials - some of whom served in Iraq a decade ago, and had friends and comrades killed by Iranian-backed militias and Iranian-provided improvised explosive devices - and the outcome has been an increasingly confrontational posture towards Teheran.
That posture has been manifested in new economic sanctions, increased support for and deference to Saudi Arabia and other of Iran's Sunni rivals, and the willingness to make a small number of military strikes against Iranian-backed groups in Syria. And, according to recent reports, the Trump administration is considering a wide-ranging regional offensive against Iran, to include increased interdiction of Iranian arms shipments headed to client forces in Yemen and elsewhere, along with more permissive rules of engagement for US naval commanders whose vessels face Iranian harassment in the Persian Gulf.
The third and related factor is President Donald Trump's intense hostility to the Iran nuclear deal. It was only over Mr Trump's strenuous objections that the US certified that Iran was in compliance with the terms of that agreement in July; there are signs - not least Mr Trump's own comments - that he plans either to decertify the deal, thereby laying the groundwork for the reimposition of nuclear-related economic sanctions, or otherwise undermine it come the next certification deadline next month. The likely effect of doing so would be to empower Iranian hardliners, create another serious point of friction in the bilateral relationship, and potentially touch off a renewed proliferation crisis should Iran respond by resuming its nuclear programme.
Together, these three factors are fostering heightened tensions on a variety of issues, and they are creating a situation in which the potential for escalation - in the Gulf, in Syria, in Iraq - is significant indeed.
To be clear, this move towards confrontation is by no means entirely the administration's fault. It is fundamentally rooted in Iran's destabilising behaviour; it reflects a predictable return to rivalry as the shared threat from ISIS fades. And there is a reasonable argument for a stronger but calibrated approach to constraining Iranian expansionism - indeed, even former Obama administration officials have acknowledged that previous US efforts have been insufficient. The problem, however, is that Mr Trump has shown little indication that he can undertake such a programme responsibly, or even that he is sensitive to the dangers.
So far, the US President's efforts to push back against Iran have been ill-considered and destabilising. In May, Mr Trump apparently decided to subcontract the confrontation with Iran to Saudi Arabia and its Sunni allies, by green-lighting - whether tacitly or explicitly - their plan for a showdown with a Qatari government whose offences included being too friendly to Iran. The predicable result was a counterproductive confrontation between America's partners in the region, which has actually pushed an isolated Qatar closer to Iran. Similarly, even if the desire for a tougher policy is not necessarily misplaced, terminating or undermining the Iran nuclear deal is the wrong way to go about it. Leaving aside the fact that nearly all observers agree that Teheran is in technical compliance with the deal, taking such a step would likely have the effect of isolating the US diplomatically - particularly from its European partners, which would have to cooperate to make additional US economic sanctions effective - while reintroducing a nuclear dimension into the US-Iran conflict. This is presumably why so many of Mr Trump's own advisers have reportedly argued against his desire to undermine the accord.
It also seems unlikely that Mr Trump understands just how risky the current trajectory of events is becoming. Although Iran has varying levels of interest in the different conflicts and countries in which it is involved in the Middle East, as a general rule these conflicts - purely for reasons of geography - matter more to Iran than they do to the US. For example, the question of who controls the area around Deir Ezzor in western Syria is of tertiary geopolitical importance for Washington; it is fundamental to Teheran, given the critical role that relationships with Syria and the Lebanese terrorist group Hizbollah play in Iranian foreign policy. Accordingly, Teheran is undoubtedly willing to play dirtier and bloodier than Washington in the competition for influence in these areas. An intensified cold war - let alone a hot one -would be far more fraught for US interests than Mr Trump likely expects.
Indeed, the move towards confrontation with Iran has exposed a fundamental tension in Mr Trump's statecraft towards the Middle East. As the President has made clear, he is not eager to invest large amounts of additional blood and treasure in a region that has proved so frustrating for America. Yet, ramping up tensions with Iran risks incurring precisely the costs and dangers that Mr Trump says he wants to avoid. An overriding theme of Mr Trump's foreign policy so far has been the effort to act tough on the cheap. The US President should understand that when it comes to Iran, this approach may well prove costly.
• Hal Brands is the Henry A. Kissinger Distinguished Professor at the Henry A. Kissinger Centre for Global Affairs, Johns Hopkins University's School of Advanced International Studies, and a senior fellow at the Centre for Strategic and Budgetary Assessments.