Eventually, America's long-slog presidential primaries will end, and the world's most powerful country will turn to the general election. And when it does, polling suggests that foreign policy and terrorism will be major issues for voters. This will naturally focus much of our national discourse, over the following several months, on Syria.

That's largely a good thing. Syria's civil war, which since its 2011 inception has become a proxy war involving much of the Middle East as well as the US and Russia, could use some attention. It is a disaster primarily for Syrians but also for the world, fueling ISIS and other terror groups, as well as the refugee crisis that is straining European unity.

But it's no secret that political discourse tends to oversimplify and distort complex foreign policy issues. That's especially a problem during campaigns, when candidates are more focused on attracting voters with appealing rhetoric than on articulating sober-minded policy proposals. That means proposing too-easy-to-be-real solutions, downplaying trade-offs, caricaturing disagreements, and, especially, ignoring hard truths.

So with that in mind, here are a few of those hard truths that are about to be obscured — and that are crucial for understanding Syria's war and the world's struggle to end it.

1) There is no magical, low-cost solution for Syria

The presidential campaign will bring nonstop promises of easy and simple ways that America can fix Syria. There is Bernie Sanders's Muslim army, for example, the Ted Cruz carpet-bombing plan, and Marco Rubio's promise of "overwhelming US force."

Those plans all share a conspicuous absence of specifics and an implied promise to easily fix Syria in ways that will have little cost for America. But no such plan really exists. All available options are costly, and none can produce a total victory.

2) Every candidate is basically proposing to maintain Obama's Syria policy

Behind the magical solutions are details that, on inspection, really just promise the status quo. This is true for Democrats as well as Republicans. Differences are mostly stylistic, or candidates promise to do something the US is already doing or will present a minor tweak that sounds good but is unlikely to substantially alter the war — for example, Jeb Bush's no-fly zone.

The core issue is that candidates need to promise a break from Obama's unpopular handling of Syria, but no one has been able to discover an obviously superior strategy. So in the meantime they're just finessing it and hoping no one will notice.

3) There is no secret Sunni army coming to save the day

Virtually every proposal, including Obama's current plan, hinges on a force of Sunni Arabs who will retake and unify the Syrian territory currently held by some combination of ISIS, Bashar al-Assad's highly sectarian army, and a patchwork of rebel groups. The argument goes that after years of sectarian killing, Sunni Arabs in Syria would only accept rule by fellow Sunnis, so sending a non-Sunni force would just allow ISIS to return and perpetuate the conflict.

But even if that is true, no such force exists — not in Syria and not elsewhere in the region.

4) Peace talks are almost certainly doomed

They're worth having anyway, if only to open diplomatic channels by which the parties can manage the conflict to make it a little less terrible. But currently, there just does not exist a mutually acceptable position for the major parties involved. And as Michael Knights of the Washington Institute on Near East Policy has pointed out, the Middle East's regional powers are primarily interested in positioning against one another, not in solving Syria or ISIS, which makes them actively opposed to finding peace in Syria.

5) The war is stuck in a stalemate, and there's no obvious way to change that

The war has been teetering between rebel advances (in much of 2014 and 2015) and regime advances (currently ongoing), but neither side is able to overturn the stalemate. The involvement of outside powers is just deepening that dynamic. My colleague Zack Beauchamp explains:

These shifts in momentum reflect the fundamental weakness of all parties. Assad has manpower problems, the rebels are deeply divided, and ISIS has managed to make enemies out of virtually every powerful actor in the Middle East. No side is strong enough to crush any other by dint of force, so gains end up being pretty temporary. Moreover, both Assad and the non-ISIS rebels are backed by actors outside of the country, who tend to escalate when it looks like their proxies are losing ground.

Indeed, a 2008 study found that that civil wars average about a decade in length and are elongated when foreign powers intervene and when they are divided between many factions, both of which apply to Syria.

6) There was maybe a window for intervening in Syria, but it's closed

Early on in the war, in summer 2012, conditions were much more favorable for a US intervention. The rebels were more unified, the Syrian state had not been so utterly destroyed, and there was no ISIS. Even Moscow thought Assad was on the verge of falling.

Had the US tipped the war in the rebels' favor then, perhaps with limited airstrikes, Syria would today perhaps looks more like Libya: a catastrophe, but one in which the per capita death rate is one-eighth of Syria's and the displacement rate only a hundredth.

But now that window has almost certainly closed: A US military intervention cannot solve the war and will only make it worse. So when discussions of blame inevitably come up, they will fairly accuse Obama of missing this window, but that blame is not a solution for today.

7) Terrorism is a fact of life. It can be mitigated but not solved.

The US has gotten very good at detecting and preventing major terror plots coordinated from abroad. There's a reason there hasn't been a successful 9/11-style large-scale attack.

ISIS has enough money and recruits that it can keep attempting Paris-style attacks, though, and it's not guaranteed that the US will necessarily maintain a 100 percent success rate in stopping them.

And it is all but guaranteed that ISIS-inspired lone wolf attacks, like the recent one in San Bernardino, will continue. These attacks are much less deadly but are extremely difficult to detect and prevent, particularly given the ease of access to guns in America. While various candidates will make promises about magic policies that will fix this, the truth is that such attacks cannot be absolutely prevented any more than we can have zero violent crime. Terrorism is a problem that can be managed and mitigated, but not solved.

8) A no-fly zone will not end Syria's war and risks making things worse

This is what analysts often call a "do-something" policy: a proposal based on the principle that "something must be done; this is something; so therefore we must do it." In other words, it's a policy designed not to solve the problem but rather to reassure ourselves that we are taking some morally satisfying action. The Council on Foreign Relations' Micah Zenko goes point by point on why the most popular do-something policy will not save Syria and is in fact more likely to make things worse.

In brief: Airstrikes only account for a fraction of Syria's deaths, a no-fly zone in the north (as commonly urged) will have little real impact, and applying a no-fly zone more broadly would risk a shooting war with Russia (again, for little benefit). Zenko adds, "As we know from UN-declared safe zones in Bosnia-Herzegovina and in sub-Saharan Africa, combatants will use it to rest, recruit, and recover, thereby placing all civilians residing there at grave risk."

9) Assad has to go, but toppling him by force will make things worse

Assad is frequently and correctly identified as the core driver of the Syrian conflict: His policies of violent sectarianism have made Syria ungovernable and given the country's Sunni majority no better option than rebellion. As long as he stays in power, the war will continue. But toppling him outright would nonetheless be a catastrophe.

Syrians are already suffering mass displacement, and with state services in many places nonexistent they face extreme poverty, disease outbreaks, and hunger. They cannot endure the collapse of what little of the state remains. In the majority of the country where Assad has lost control, territory is divided among many different rebel groups. Were Assad to fall, they would lose their common enemy and could turn on one another. In such conditions, ISIS would almost certainly come out ahead.

10) Any viable peace deal will probably let Assad stay on in some capacity

Given the above, the only solution is for Assad to step down in a way that preserves the Syrian state and its infrastructure, which then transitions to inclusive democracy. That's not something you can just snap your fingers and do; it would take months or years to implement. During that time, Syrians desperately need state institutions that can alleviate the humanitarian crises, peacefully disarm or absorb rebel groups (this was a key lesson of Libya), and fight ISIS.

Maybe Syrian regime elements will decide to eject Assad in a coup and embrace a transition to democracy. But regime power centers have repeatedly signaled that they stand with Assad, no matter how suicidal or costly his policies. The Alawite ruling class fears what might happen to them if Assad loses power. They will likely only accept peace if Assad is granted amnesty and probably some symbolic position in the government.

This is extremely distasteful — there is probably no single person responsible for more human suffering in the 21st century — but if we want to end that suffering, it may be necessary.

11) The Kurds are great, but they are not a solution

A common proposal is that America must show more support for the Kurdish groups who have been both reliable American allies and effective anti-ISIS and anti-Assad fighters. It is true, they have. And there is a valid debate to be had as to whether the US is too deferential to Turkey, which is hostile to Kurdish groups due to its country's own Kurdish rebellion. But most of Syria is Arab, not Kurdish, and Kurdish groups have shown neither willingness nor capability to conquer vast stretches of Syrian Arab territory.

12) American allies are escalating the conflict

This particularly includes Turkey and Saudi Arabia, along with other Gulf states, which are more focused on toppling Assad and on trapping Iran in a quagmire than they are on ending Syria's war. The US has been cajoling and pressuring these allies to change their behavior, to occasional success, but ultimately these countries are putting their own interests first.

This isn't something political candidates want to admit, because there is a political culture in America of deference to Middle Eastern allies (which are frequently said to understand American interests better than the US president, regardless of his party). Challenging that culture would force the candidate to either argue for jettisoning the ally or explain why that ally is worth the trade-offs — both politically costly maneuvers.

It would also require admitting that American power has limits: We can't even dictate policy to our allies, so we certainly can't to our adversaries.

13) Russia and Iran have a say in what happens in Syria, whether we like it or not

Pundits and politicians often confuse analytical findings with moral judgments. It is common to argue that Russia and Iran are bad actors in Syria (as indeed they are) and that therefore the US should choose a policy of maximal belligerence toward them because it is the most morally satisfying course.

Unfortunately, such a policy would not fix Syria and would bring considerable downsides, including the risk of war between the world's two leading nuclear powers. Of course, negotiating with Russia and Iran also carries downsides. But the point is that even though we dislike these countries, they are major components of the war, and we have to acknowledge this reality, painful as it may be, if we want to do anything about Syria.

14) Vladimir Putin is not a chess master genius whose defeat will bring peace

This myth is a reassuring one because it gives Americans a villain to blame for everything, and the promise of an easy solution: If only the villain can be confronted, then everything else will fall into place. Putin's Syria strategy is indeed making the conflict worse, perpetuating violence, and entrenching Assad. But his intervention, at best, is assuring a stalemate at significant cost to Russia at a time when its economy is cratering.

Putin has little control over Assad, whom he reportedly tried in December to push out; the Syrian leader has been playing Russia and Iran off one another for months. The frequent demand that America "stand up to Putin," however it is defined, is not a path to a solution for Syria's war, but it is a very appealing political statement, so expect to hear it many times over the next year.