As the United States struggles to begin a serious discussion about how best to deal with the threat posed by terrorist groups in general and Islamic State militants in particular, Russ Feingold is offering answers based on decades of experience and a deep understanding of all the issues that must be addressed. And it may be that the most important of these answers is this one: “[If] we are to win this fight, we cannot repeat the mistakes of the past with yet another rush toward a full-scale ground invasion led by tens of thousands of American troops.”

“The last invasion of Iraq cost our country trillions of dollars, thousands of American lives and greatly destabilized the region to the terrible detriment of our security,” argues the former senator from Wisconsin, who warns that “our response to the threat from ISIL cannot be reactionary or one-dimensional.”

The right combinations of expanded intelligence-gathering, the ending of arms sales and freezing of assets, diplomacy, development aid, and carefully-targeted military inventions—“a modern, comprehensive and bipartisan strategy that harnesses all of America’s strengths”—can work, says Feingold. But the combinations must be informed by our experience and our understanding of past mistakes, current challenges, and future possibilities.

Feingold brings that understanding and experience to the current debate. He served 18 years in the Senate Foreign Relations Committee, where he chaired the subcommittee of Africa and was a key player on subcommittees dealing with Near Eastern Affairs, South and Central Asian Affairs, and East Asian and Pacific Affairs. He recognized the folly of giving George W. Bush and Dick Cheney the authority to order the invasion of Iraq, joining the minority of senators who wisely opposed a war based on false premises. Because he had traveled so extensively in Africa and the Middle East, because he had studied the intelligence rather than embracing the fool’s mission of neocon fabulists, Feingold recognized the danger of military intervention, ongoing occupation, and regime change without a plan for what would come next. And he kept speaking up, as a senator and a citizen.

In 2012, he wrote an acclaimed book on international affairs, While America Sleeps: A Wake-Up Call to the Post-9/11 World (Broadway Books), which Democrats and Republicans hailed as an outline for an engaged and effective response to global challenges. Former senator Robert Kerrey said Feingold’s writing and thinking prepare “citizens to engage in the national debate about a crucial part of our foreign policies.” Feingold, himself, engaged in 2013, accepting an appointment as the US State Department’s special envoy for the Great Lakes region of Africa—a role that put him in the thick of the global discourse about averting violence, extending democracy, addressing poverty and political instability, and responding to terrorist threats.

Feingold left that position early in 2015 to run again for the US Senate, running a race in which polls put him ahead of the man who beat him in 2010, Senator Ron Johnson, a Republican hawk who is so enthusiastic about sending US ground troops back to the Middle East that headlines on news stories about the senator regularly report on his latest “calls for war.” Like many Republicans and some Democrats in Washington, Johnson looks to past invasions and occupation as models.

Though he chairs the Senate Homeland Security and Governmental Affairs Committee, Johnson tends to look backward rather than forward when it comes to combating terror threats. He borrows pages from Dick Cheney’s more-war playbookechoing the most hawkish of the 2016 presidential contenders.

Feingold rejects repeat Cheneyism.

He recognizes that remaking the mistakes of the past is foolhardyand dangerous.

“Invading Iraq constitutes one of the biggest foreign policy blunders in the history of the United States, and proved that we cannot invade our way to safety in the 21st century. So our response to the threat from ISIL cannot be reactionary or one-dimensional,” Feingold wrote in an article that appeared in the Milwaukee Journal Sentinel. “And as we saw in the years after the Iraq invasion, our military cannot act as a government in the middle of a country that lacks stability and democracy, because those conditions are a recipe for our troops to become targets for insurgents and lightning rods for unstable, anti-America sentiment. We also must avoid the type of mission creep that could cause our troops to remain indefinitely.”

Feingold is not proposing inaction.

He’s proposing savvy and considered engagement that has a chance to work.

“[We] need a modern, comprehensive and bipartisan strategy that harnesses all of America’s strengths,” explains the former senator. “The attacks in Paris and San Bernardino are a reminder that ISIL, al-Qaida, and their affiliates threaten all of us, but that we can only destroy them by working with our partners and allies, through cooperative intelligence, economic, diplomatic and military efforts. We will get this done together.”

Feingold has a point.

It is possible to respond in rational and effective ways to even the most daunting of global challenges. It is possible to keep Americans safe while maintaining basic liberties. Feingold has always recognized this reality. The key is to bring this recognition to the forenot just in the 2016 campaign but in the policies that must be about a lot more than repeating old fantasies and making old mistakes.