The cost of the U.S. fight against ISIS as of May 29, 2015. See the current cost.

With ISIS in the news again recently and new fears about abilities to contain the threat, many are taking a new look at what the U.S. role in the conflict should be. We're also taking another look at what this fight is costing us. 

As of the end of May 2015, the United States has now spent over $4.3 billion fighting ISIS -- and that doesn't include the hundreds of billions on the Iraq war, the money that we've spent allegedly building the Iraqi government and military so that these threats won't keep cropping up. It also doesn't include everything we've spent aiding Syrian rebels.

As we've noted before, the initial fight in Iraq was meant to cost no more than $60 billion -- and is now at more than $818 billion. With pressure to contain ISIS mounting, some of the higher estimates of what the U.S. could spend fighting ISIS -- as much as $20 billion a year or more -- could become a reality.

Before that happens, consider the following:

• 85% of Americans expressed concern that the fight against ISIS could become another costly, drawn-out engagement.
• As strong as the U.S. military is, even the most effective military response may not present an effective long-term answer to extremist groups like ISIS, and could very likely make the situation worse.
• The Pentagon already has a $30 billion slush fund in its war budget. Any additional funds to fight ISIS could be found within the existing Pentagon budget.

The cost of war isn't just measured in dollars -- it can be measured in lives lost and forever changed, and in change for the better here at home that goes unrealized because we choose not to invest in our own future.