ISIS is gaining momentum in the worst possible way

In the year since the Islamic State terror group tore through the Middle East and claimed Iraq's second-largest city, the US has been scrambling to come up with an effective strategy to defeat the militants.

Meanwhile, Islamic State (aka ISIS, ISIL, and Daesh) is winning by settling in as Iraq and Syria crumble.

"A year after the Islamic State seized Mosul, and 10 months after the United States and its allies launched a campaign of airstrikes against it, the jihadist group continues to dig in, stitching itself deeper into the fabric of the communities it controls," Ben Hubbard of The New York Times reports.

The Times, citing interviews with residents, notes that ISIS "is offering reliable, if harsh, security; providing jobs in decimated economies; and projecting a rare sense of order in a region overwhelmed by conflict."

And by doing so, they are increasingly winning over reluctant civilians.

"It is not our life, all the violence and fighting and death," a laborer from Raqqa told the Times. "But they got rid of the tyranny of the Arab rulers."

'They've clearly got the best battle plan'

After a US general insisted that the ISIS was on the defensive in December, the militants seized Ramadi, the provincial capital of Sunni-dominated Anbar province, successfully crippling Iraqi security forces that significantly outnumbered ISIS fighters. The group then went on to take Palmyra, a strategically and historically significant town in Syria, from the regime of dictator Bashar Assad.

"People inside DC are hanging onto the myth that ISIS isn't that good, but they're missing that what ISIS has done shows an extraordinary capability to conduct integrated military operations," Christopher Harmer, a senior naval analyst at the Institute for the Study of War, told Business Insider.

Harmer noted that ISIS has proven that it can coordinate military activity across multiple fronts, moving fighters within and between Syria and Iraq, transporting vehicles across borders, sharing expertise in how to build improvised explosive devices, and coordinating even small battles from the top down.

"They've clearly got the best battle plan and nobody that's fighting against them has a logical plan on how to defeat them," Harmer said. "It is beyond obvious to any observer of what's happening that ISIS' strategy is clearly more effective than the American strategy to defeat it."

The Soufan group pointed out in a note this week that three key assumptions the Obama administration has modeled its anti-ISIS strategy around haven't held up very well over the past year.

The Iraqi army is still incapable of beating back ISIS and retaking Mosul, the Shia-dominated government in Baghdad has been reluctant to arm and train Sunni fighters in Iraq out of fear that they'll one day rise up against Baghdad, and the US hasn't been able to effectively counter ISIS' online propaganda that lures thousands of foreign fighters into its ranks.

'Baghdad and Iran are opposed to us training Sunnis'

Obama recently announced an expansion of the current US strategy in the Middle East, pledging to send 450 more troops to Iraq in a push to train the country's battered security forces to retake Ramadi.

But Michael Pregent, a terrorism analyst and former US Army intelligence officer in Iraq, explained to Business Insider earlier this week why this strategy is likely doomed to fail.

He recently wrote that while the Obama administration is correct to think that arming and training Sunnis to defend their own territory is the only viable way to beat back ISIS advances, the political situation in Baghdad (not to mention Syria) are obstructing the plan.

The Shia-led government in Baghdad is vetting the recruits who want to join the Iraqi security forces, and they have been looking for any connections to Sunni political leaders and Baathists who formerly supported dictator Saddam Hussein.

"You can send more American advisers, but until they're training Sunnis, they're not going to make a difference in the fight against ISIS," Pregent told BI. "Baghdad and Iran are opposed to us training Sunnis, and the president cares about the nuke deal."

Obama acknowledged earlier this week that the US did not have a "complete strategy" to beat ISIS, a Sunni extremist group.

This is especially clear when looking at Syria, which is staunchly backed by Iran and largely ignored by the Obama administration while Obama pursues a "once in a lifetime opportunity" to finalize a nuclear deal with Iran, the Syrian regime's main backer.

The US-led anti-ISIS coalition has been carrying out airstrikes in Iraq and Syria and training Iraqi security forces, but this hasn't been enough to win the ground fight against the militants.

So Shia militias backed by Iran have stepped up, as they've proven to be a more effective fighting force than the Iraqi army. But the Shia militias have been accused of committing atrocities against Sunni civilians as they battle ISIS, which helps ISIS' efforts to convince Sunnis in Iraq and Syria that ISIS is the only group that can protect them against Shia militias and a government that is skewed toward Shiites.

"The political solution is to have a unified, stable, neutral Iraqi central government that represents the interests of the people," Harmer said. "If we have a Shia militia inside Iraq that is loyal to Tehran, that is not helping achieve the political outcome. From a military perspective, the Shia militias are a good thing. From a political perspective, it's destabilizing."

'Extend and pretend strategy'

The US might be out of good options now, and the Iraqi government doesn't seem willing to push the Shia militias out of the country. And since Iran is so closely aligned with Syria, the Assad regime isn't pushing out any Iranian-trained Shia fighters there either.

Yaroslav Trofimov wrote in The Wall Street Journal last month that the US now has three options in the fight against ISIS: carry on with what they're already doing, escalate the fight, or give up. And none of those options are appealing.

Harmer said the situation in Iraq and Syria is going to get worse before it gets better.

ISIS continues to grow, and it's successfully marketing its "caliphate," an Islamic empire that aims to unite the world's Muslims under a single religious and political entity, as a utopia to thousands of foreigners who then travel to ISIS territory to contribute to the group's cause.

"Enemies, like government soldiers, the police and those who do not fit in, such as minorities or elites, flee or are killed," The Times notes. "What remains are mostly Sunni Arabs who try to continue their lives with little disruption."

The plan is not likely to be sustainable in the long term, bu tit's working right now.

"Eventually, at some point, the caliphate will collapse because there's not enough people who want to live in that type of a religious theocracy," he said. "But it's not going to collapse anytime soon. Their message is resonating with enough foreign fighters that they're getting a significant influx of foreign fighters. … There's an ideological and operational coherence."

And while ISIS thrives, the US seems to lack coherence with its strategy.

"People on active duty like to say we've got an extend and pretend strategy," Harmer said. "We keep extending failed policies and pretending they are working."

Michael B. Kelley contributed to this report.