I know a better way to fight ISIS. It starts with an idea that should appeal the better angels of both hawks and doves: National service for all 18- to 28-year-olds.

Require virtually every young American -- the civic-minded millennial generation -- to complete a year of service through programs such as Teach for America, AmeriCorps, the Peace Corps, or the U.S. military, and two things will happen:

1. Virtually every American family will become intimately invested in the nation's biggest challenges, including poverty, education, income inequality, and America's place in a world afire.

2. Military recruiting will rise to meet threats posed by ISIS and other terrorist networks, giving more people skin in a very dangerous game.

(RELATED: What Should the U.S. Do About ISIS?

This may seem like a radical plan until you compare it with two alternatives: the status quo, which clearly isn't working, or a military draft, which might be the boldest and fairest way to wage the long war against Islamic extremists.

Remember in September when the beheadings of two Americans galvanized the nation against ISIS? President Obama, who had dismissed ISIS as a "JV team," promised, "We will degrade and ultimately destroy" the Islamic State. Nine months later, ISIS is winning.

In a piercing analysis, my colleague Kristin Roberts cut through the Democratic and Republican spin to describe two options we face in dealing with a "lethal, strategically smart, and tactically effective adversary."

The United States -- under Barack Obama or the next president -- can choose to sit this out, to let Sunni fight Shia and then Wahhabi fight Sunni until some resolution is found. The risk associated with this option is that what remains standing could be the slave-holding, woman-raping, Christian- and Jew-killing territory known as the Islamic State, which will not pause to relish victory but instead set sights on Europe and the United States.

Or the United States—under Barack Obama or the next president—can choose to engage aggressively, hoping that a greater assault than what's being accomplished by U.S. airpower and on-the-ground training will stop ISIS from destroying the governments in the region that still take Washington's calls. The cost of this choice is great: money and, more importantly, blood.

If you prefer the first option, this column isn't for you.

If you choose the course of conflict and sacrifice, understand that a "greater assault" would require considerably more U.S. aircraft, military advisers, and combat troops. Estimates for "boots on the ground" vary from 10,000 (Sen. John McCain and General Anthony Zinni, former head of Central Command) to 25,000 (military analysts Kim and Fred Kagan) in Iraq alone—and as high as 100,000 to completely destroy ISIS (former CIA Deputy Director Michael Morell).

(RELATED: What ISIS Really Wants)

Whatever the number, it would be big—and would remain so for years, if not decades. Obama already is eying a network of bases in Iraq, which may need to remain indefinitely.

Also understand that a sustained fight against ISIS would demand a new stream of troops. This country has already asked too much of too few. Redeployments -- cycling the same men and women through combat again and again and again and again and again -- is unsustainable and unfair. Just a tiny fraction of society lives with the results: physical and mental injuries, personal finance and career problems, retirements and long-term disabilities.

One way to truly level the costs would be to reinstate the military draft and impose a war tax, the cause of liberal New York Democrat Charles Rangel, an 84-year-old Korean War veteran. "When I served, the entire nation shared the sacrifices through the draft and increased taxes, but today, only a fraction of America shoulders the burden," he said. "If war is truly necessary, we must all come together to support and defend our nation."

The Draft Act is highly unlikely to be law, given the nation's post-Vietnam resistance to the mandatory military service and the relative success of an all-volunteer armed forces. Which leads me to the year-of-service plan: It stops far short of a draft while drawing on the ethos of communal sacrifice.

I spoke about the concept with retired Gen. Stanley McChrystal, who commanded forces in Afghanistan and Iraq and now chairs the Franklin Project, part of the Aspen Institute that is trying to position a year of full-time national service -- a service year -- as a "cultural expectation, a common opportunity, and a civic rite of passage for every young American." His logic tracks with mine.

First, he's not sure Obama is fully committed to the goal of destroying ISIS.

Second, if this president or his successor gets serious about ISIS, McChrystal said the effort would require an international coalition and more U.S. troops. "Even if we didn't need a draft" to drum up the required troops, McChrystal said, "I would argue we need a draft, because it forces national commitment."

He knows a draft isn't in the cards. A national commitment to "service years" would prime the pump of an all-voluntary military, McChrystal said, while uniting the country in sacrifice.

It's not a draft, but it's not nothing.

"A problem in America is we've let the concept of citizenship diminish into a series of gripes," McChrystal told me. "One of the ways we can rebuild that sense of ownership, sense of shared ownership, is through experience, and so I believe that every young person deserves—I don't think this is an onerous thing—deserves the experience of being part of something bigger than themselves."

Bowing to political realities in risk-averse Washington, the Franklin Project aims to make a service year a social expectation rather than a legal requirement. I would mandate it. So would McChrystal—if he had his way.

While ISIS and other terrorist groups are having no trouble recruiting suicide bombers, McChrystal said, Americans are struggling to redefine their national identity for the 21st century. "A year of service for young Americans would be a step," he said. "Not a panacea, a step."

I think we should take it.

NOTE: The original version of this column overstated McChrystal's estimation of troops required to eradicate ISIS. He did not confirm estimates made by others.

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