In recent Capitol Hill testimony, all but overlooked in the pandemonium created by the coronavirus pandemic, US Marine Corps General Frank McKenzie offered vital insights into the conduct of yet another of the United States’ “forever wars” — this one in Iraq.

Almost half a century after the Iranian Revolution and the Iran-Iraq War, three decades after the United States chased Saddam Hussein out of Kuwait and almost two decades after the US-led invasion of Iraq, McKenzie offered some basic rules governing Washington’s policy of permanent military intervention in Iraq.

Iraq, irreparably weakened by decades of war, political fratricide and deprivation, continues to tempt the intervention of outsiders. Iraq may be the prize but it is merely the arena where the contest between more powerful states is being waged.

Washington’s deployment in Iraq, and indeed throughout the region, is viewed by US strategists as a manageable, potentially useful distraction from the main challenges to US global influence — China and, to a lesser extent, Russia. If countries are to see an advantage in allying with the United States in this global confrontation, explained one senator, Washington must maintain the credibility of the US staying power in Iraq.

Unlike the battle against the Islamic State, the goal adopted by the US military in Iraq is not a classic military victory but rather the far more limited achievement of frustrating the efforts of Iran and its Iraqi allies to expel the United States from the country. In Iraq, like Syria next door, Washington would consider it a victory if Iran and its local allies simply stopped contesting its presence in the country.

Iran, however, like the combatants in Syria, has not received the memo.

“Since May 2019,” McKenzie noted, “Iranian proxies and Shia militia groups in Iraq have increased attacks on US interests and conducted scores of unmanned aerial system — aerial unmanned system reconnaissance flights near US and Iraqi security force bases.

“[The] Iranian regime desire[s] to continue malign activities that threaten lives, destabilise sovereign nations, threaten freedom of navigation and regional commerce, global energy supplies and the global economy itself.

“At [US Central Command] we recognise that, so long as the US applies diplomatic and economic pressure, the joint force must be postured to deter Iran from deploying the military element of power to counter our actions.”

All conflicts have rules governing the conduct and the strategies of combatants — ranging from total war to more benign forms of confrontation. These “rules of the game” are a defining feature of the forever wars that dominate the Middle East.

The rules of the game in Iraq are limited to winning a tactical advantage in what is viewed by both sides as a never-ending conflict far short of victory. By their very nature these rules are not explicit and articulate. The antagonism underlying relations simply prevents such clarity.

McKenzie acknowledged that the US policy of economic warfare and international isolation leaves Iran only one arena — the military sphere — to conduct a defensive battle against Washington’s policy of “maximum pressure.”

Washington defines Iran as the head of the snake but US efforts in Iraq are directed principally against Iraqi-deployed militias supported by Tehran.

Iran has deputised its Iraqi proxies to conduct its military confrontation with the United States, increasing their limited attacks in recent months against the Green Zone and US military installations around the country.

Washington has failed to deter such attacks and when US President Donald Trump broke the rules in January by assassinating Iraqi Major-General Qassem Soleimani, Iran did not retreat. Instead, it upped the ante, employing for the first time its own arsenal of ballistic missiles against US bases in Anbar and Kurdistan.

Following this confrontation, McKenzie said that a “rough form of deterrence, what I would call contested deterrence… at the level of state-on-state attacks” had been re-established.

As a consequence, direct confrontation between Iranian and US forces appears to be off the table, for the moment.

McKenzie stressed that killing US personnel is an explicit American “red line” but, as recent US casualties attest, this line, too, has been crossed. McKenzie admitted that Iran lacks “a good understanding of where our red line is.” As former US President Barack Obama discovered to his chagrin, a red line that is not defended is no line at all.

In a conflict governed by the rules of the game, breaking the rules is built into the system. Ambiguity and opacity make such a system of relations inherently unstable. The rules of the game work, until they don’t.

Soleimani’s assassination broke the rule, practised not out of any affection for the Iranian leader but rather because his assassination had long been deemed by US officials to be counterproductive.

“Killing Soleimani might have made sense,” explained retired Marine Corps Colonel Andrew Milburn, a special operations leader, “if it was part of an overarching plan but the evidence so far indicates that there is no such plan beyond a willingness by the United States to trade blows.”

Israel is the premier practitioner of this policy of “wars between wars” but, unlike Washington, Israel is engaged in a century- long conflict — a battle built into the very fabric of the Middle East.

Israel has adopted the policy of rules of the game with adversaries as varied as the Palestine Liberation Organisation, Hezbollah, Hamas and Iran. Both sides find this form of warfare more tolerable than total war or surrender and retreat.

For Washington, to adopt Israel’s strategy of the Iron Wall reflects a strategic mismatch that promises for Washington not victory but rather bloody and endless stalemate.