WASHINGTON — It looks as if President Trump is going to get his military parade after all. The last time our forces paraded across Washington was in 1991, to hail our triumph in the Gulf war. Unfortunately, there hasn’t been much to celebrate in our foreign policy since — unless you count the 15-year anniversary, on Tuesday, of the start of the Iraq war.

I don’t.

As a veteran of Afghanistan, I wish this weren’t the case. No patriot wants to see us fail. But America’s approach to the world just isn’t working to make us safer and more prosperous. And President Trump isn’t helping. We need a more effective and realistic foreign policy.

The Iraq war is just the worst in a string of failures. They range from that destructive regime-change mission in Iraq and a later such effort in Libya to the ill-fated nation-building project in Afghanistan, and all the way back to the dangerous enlargement of NATO in the 1990s and 2000s to include countries on Russia’s doorstep. In the process, nearly 7,000 American troops have been killed and tens of thousands wounded, and we’ve spent trillions of dollars — all while failing to achieve our strategic objectives.

Underlying all of these failures is the view, endorsed by both parties, that we need an active military presence around the globe to shape what happens almost everywhere. But it doesn’t matter how well funded our Pentagon, how brave our troops or how well intentioned our diplomats are. So long as we keep tinkering with this flawed operating system, we will continue to fail.