The Taliban not only has the "momentum" after the most successful year in its campaign against the United States and the Kabul government. "The Afghan insurgency can sustain itself indefinitely," according to a briefing from Major General Michael Flynn, the top U.S. intelligence officer in the country. "The Taliban retains [the] required partnerships to sustain support, fuel legitimacy and bolster capacity."

And if that isn't enough, Flynn also warns that "time is running out" for the American-led International Security Assistance Force. "Regional instability is rapidly increasing and getting worse," the report says.

Since General Stanley McChrystal took over as top commander in Afghanistan, there have been a series of dark appraisals about the state of the war. In August, McChrystal warned of an "urgent need for a significant change to our strategy and the way that we think and operate." A report recently obtained by NBC News said Afghanistan's security forces won't be ready to fight the Taliban for years – if ever. Earlier this week, Flynn issued a white paper complaining that "eight years into the war in Afghanistan, the U.S. intelligence community is only marginally relevant to the overall strategy."

But Flynn's December 23rd presentation on the "State of the Insurgency: Trends, Intentions and Objectives" may be the gloomiest public assessment of the war yet. The "loosely organized" Taliban is "growing more cohesive" and "increasingly effective." The insurgents now have their own "governors" installed in 33 of Afghanistan's 34 provinces. And the "strength and ability of [that] shadow governance increasing," according to the presentation. The Taliban's "organizational capabilities and operational reach are qualitatively and geographically expanding."

Improvised bomb "events" have nearly tripled since 2007 – 7228 this year, compared to 2718 two years ago. The bombs have grown bigger – the majority are now 25 pounds or more. "80 to 90 percent" of them are made with homemade fertilizer, rather than military ordnance. That makes it much harder to track and block the distribution of the bomb-making material. Add to that steady supply of cash, thanks to the drug trade and the corrupt Kabul government, and a glut of weapons and ammunition," and it becomes clear why, in Flynn's words, "the insurgency is confident... looking toward post-ISAF Afghanistan."

The presentation also cast doubt on some of the war's stated central aims. The Obama administration has repeatedly said that additional troops are necessary to prevent a Taliban takeover of Afghanistan – which would then allow Al Qaeda the re-establigh its safe haven there. According to interviews with detainees, however, the insurgents "view Al Qaeda as a handicap – a view that is increasingly prevalent." The Taliban feel they have to "manage [the] relationship with AQ to avoid alienating Afghan population, but encourage support from [the] global jihad network."

Flynn's presentation also, indirectly, warns that one of the central U.S. tactics in Pakistan – drone strikes against suspected militants – could backfire. "violations of Pakistan sovereignty may contribute to radicalizing the population and diminishes credibility of the GoP [Government of Pakistan]." Such violations "demonstrat[e] an inability of the government; perception they cannot protect their own; exacerbates anti-western sentiment."

Within military circles, there's a sense that Flynn may be underplaying recent American successes in Helmand province and elsewhere. And Flynn does note that there's still hope for the American effort in the region. "We have a key advantage – [the] Taliban is not a popular movement (yet)," the report says. What's more, there are "persistent fissures among insurgent leadership at local levels" and an "over-reliance on external support."

Exploiting those fissures – and beating the Taliban – will "requir[e] operating / thinking in a fundamentally new way."