In the war on Islamist jihadi threats, America has focused on defeating the states that give jihadis greater resources and reach. That must continue to be the focus.
The Taliban regime in Afghanistan was a Sunni caliphate that hosted al Qaeda which struck America on 9/11 (and earlier, of course) was destroyed in our first offensive of the War on Terror in 2001.
While some grow tired of this long war, it is simply a fact that our defeat in Afghanistan will embolden our enemies and give them back their sanctuary to use local resources to kill us in our homes again. Indeed, their victory after such a long fight will encourage future jihadis to endure long fights with the confidence that they can win eventually with Allah's blessings on their side.
The Saddam regime in Iraq had a history of both backing terrorists and being a direct threat to our allies and interests. And given Saddam's increasing reliance on Islamic ideology to bolster his authority, destroying the Saddam regime in 2003 was a campaign in the war against terror in both taking a piece of the board for our enemy and making Iraq an ally in the War on Terror.
Indeed, the Obama administration's initiation of Iraq War 2.0 against the ISIL caliphate that had exploded across Iraq in early 2014 after rising in Syria validated the original war in its belated recognition that we had something good to defend in Iraq. Iraqis have been the bleeding edge of this war, fighting our common jihadi enemies with our support.
Unfortunately, Iran took the opening America left between leaving Iraq in 2011 and the late 2014 start of Iraq War 2.0 to burrow into Iraq. And Iran has enhanced their role in Iraq by sponsoring Hezbollah-like militias in Iraq that on the surface are to fight ISIL but which are in fact for expanding Iranian influence and military options within Iraq.
Fighting to defeat the ISIL caliphate in Syria expanded while the fight in Iraq advanced. This fight against ISIL supplanted the original fight against Assad (which is a terror-supporting state with a lot of Iraqi, Lebanese, American, and Israeli blood on its hands) that took the form of tentative and sporadic help for anti-Assad rebels.
But in the face of Iranian help for Assad (money, advice, and Shia militias recruited from Syria, Pakistan, Iraq, and Afghanistan) and direct Russian intervention since late 2015, Assad has endured in a core Syria of western Syria.
America has skirmished with Iran in Syria and this will increase as ISIL is defeated in Syria, and as Iran attempts to lead the Syrian government back into the regions ISIL is pushed out of because of the American-led offensive against ISIL in the east.
In Libya, in the space opened by the destruction of the Khadaffi regime in 2011, ISIL opened a branch of the caliphate. In time, our firepower support helped local allies end that sanctuary based around Sirte and scatter the jihadis to southern Libya away from most forces capable of taking them on (although not out of range of a B-2 strike in the waning days of the Obama administration).
America helps in other places, of course. But in those areas local forces are able to fight jihadis on their own with either military or police and intelligence assets in lower profile struggles.
Really, our main efforts have focused on the sanctuaries and caliphates that allow jihadis to move from terror to state status. That must continue.
We must defeat ISIL and prevent the rise of caliphates in Syria, Iraq, and Afghanistan.
We must still defeat the Alawite (sort of Shia) terror-supporting regime that is represented by Syria's Assad and his Iranian allies (Russia is involved but is no friend of jihadis, focusing narrowly on their foothold on the eastern shore of the Mediterranean Sea). We must transition from defeating ISIL in Syria to defeating Assad.
The biggest caliphate to be defeated is the sponsor of so much chaos in the greater Middle East region (and if they get their way, in our region)--Iran.
We have lived with this Shia Persian caliphate for so long that we forget that this is what a Sunni caliphate could look like if left intact for decades on end--a hate-filled state with state resources on the cusp of getting nuclear weapons and able to use the shield of UN membership to sow death and destruction in the caliphate's interests.
So while we must surely prevent the rebirth of caliphates in Afghanistan, Iraq, and Syria (and keep one from rising in other areas in the first place by supporting allied governments); we must take on the Shia caliphate of Iran that we should not accept as a fact of life just because it has endured for so many decades now.
President Trump seems to have made the decision to take on Iran, which has made many of our Gulf Arab allies breathe a sigh of relief.
The defeat of Iran will weaken Hezbollah in Lebanon which is a mini-Shia caliphate and the weaken Hamas in Gaza, which is a little Sunni caliphate backed by Iran.
With the defeat of Iran, unrest in Afghanistan, the Gulf, Iraq, Syria, and Lebanon will be reduced.
Will this lead to peace and stability in the region? No. Iran isn't the only problem. But consider that in the time Iran has become a major threat to peace in the region, Arab states have come to accept Israel as a neighbor who can be of help in economic and security areas. So even that source of tension and wars will remain low at least in the mid-term.
If this path to the defeat of the caliphates waging war on the West is successful, there will still be caliphates, namely Saudi Arabia and Pakistan. But they are at least partial allies who, while they are sources of jihadi rage, also fight jihadis for self-protection and to satisfy our demands for action.
We can continue to push (carefully, given Pakistan's nukes and Saudi Arabia's oil production) these two caliphates to rein in and reduce jihadi influences that leak out and spread the hateful impulses to murder little girls in concerts.
The War on Terror was a long war before 9/11. It still is and still will be after ISIL is defeated and scattered.