I've encountered the Brown article before. Averaging the $3.6 trillion spent to-date since 2001, we're spending $240 billion per year on war in the Middle East.

For perspective:

* Hillary Clinton's campaign platform included a decent infrastructure bill - allocating $250 billion over 10 years.

* NIH is estimated to spend $8 billion this year on cancer and cardiovascular research - the leading causes of death in America, killing over 1 million people each year.

This Wikipedia article suggests about $800B. But the Reuters article you cite says $2T to $6T is the eventual cost.

https://en.wikipedia.org/wiki/Financial_cost_of_the_Iraq_War

Accounting is a creative endeavor.