For decades after the end of the Second World War, the United States maintained a “two-war” defence doctrine. The military organised its capabilities around the idea that it should be able to fight two conventional wars, in two separate theatres, at the same time.
That, after all, had been the reality in the Second World War, when the US had to fight in Europe and the Pacific simultaneously.
The doctrine came to an end in 2010, and in the 60 years that it was active, it was never enacted. The nearest the US came in recent history were the two wars in Iraq and Afghanistan, neither of which were conventional wars for long. Indeed, it was the inability to win those wars that finally pushed the US to change its policy.
A similar doctrine appears to be taking shape in Saudi Arabia, but the other way around. The kingdom is having to ramp up its military presence in response to multiple threats, not to meet some future perceived threat.
Saudi Arabia doesn't have the advantages that the US has long enjoyed, hidden away behind two oceans. In fact, Saudi Arabia faces serious challenges on at least three of its borders.
There is the long, porous border to the south with Yemen, currently the focus of its most serious military effort. There is the eastern flank, facing regional rival Iran. And there is its long northern border, the majority of which has Iraq on the other side. Only to the west, across the Red Sea, are there clear allies in Egypt and Sudan.
Saudi Arabia has not yet articulated its defence posture. But it does look as if it has taken the two-war doctrine as a starting point.
The Northern Thunder joint military exercises it is conducting with 20 other countries, touted as the largest joint military exercises ever conducted in the region, are a pointed message to its adversaries, whether states (Iran), regimes (Syria) or groups (ISIL).
That it is taking place in Saudi Arabia’s north is no coincidence. With a serious war underway to the south, the kingdom is seeking to show that it can, despite suggestions, fight on two separate fronts.
After all, if the country can project power with Northern Thunder, what is to stop it using that power farther north?
The obvious place for that power projection is Syria. Earlier this month, a Saudi official, Brigadier General Ahmed Al Asiri, suggested the kingdom could send ground troops to Syria to fight ISIL – although it is likely to seek support from its allies as well, some of whom are involved in Northern Thunder.
Taken together with other elements – Saudi fighter jets are now stationed at Turkey's Incirlik base, close to the Syrian border – it is hard to avoid the message that Saudi Arabia and its allies are prepared to involve themselves in the Syrian civil war, if need be.
But there’s a second part to any new defence doctrine, and that is the political aspect. Saudi Arabia’s new muscular military posture requires close cooperation between allies.
Northern Thunder, after all, is a follow-up to Abdullah Sword, Saudi Arabia’s 2014 military exercise that was, at the time, the largest it had ever conducted.
Abdullah Sword involved all the GCC countries except Qatar. Northern Thunder builds on it, expanding Saudi’s list of allies further.
The message is unmistakable. The Saudi-led coalition is expanding, not diminishing.
And it is in that that we can discern the real intention behind Northern Thunder. The Saudis are seeking to use the military exercises as a way to deepen the political coalition against Iran and any future Russia-Syria-Iranian axis.
Problems like Iran and Syria don’t have long-term military solutions. Iran’s re-emergence is not a one-off event; it is a process that will play itself out in various ways, affecting political alliances and diplomacy.
Saudi Arabia may be seeking to send a strong message to Tehran that it can defend itself against external aggression – even while involved in a conflict in which Iran is a proxy – but it is also preparing for the much longer political and diplomatic fight.
By assembling a 20-country coalition, Saudi Arabia is gathering its allies close, preparing to deepen ties between it and the Muslim world, so that when the inevitable diplomatic confrontation takes place with Iran, it will have the political capital to react.
That is the real intention behind Northern Thunder. The message being telegraphed is not merely that Saudi Arabia is ready to defend itself, but that it does not intend to do so alone.
Once the war games begin in northern Saudi Arabia, it will not be the strikes of lightning that matter so much, as the gathering of the clouds which precedes it.
On Twitter: @FaisalAlYafai