On May 8, 1945, the Allies celebrated victory over the Axis powers with triumphant parades and hopeful speeches in major European and American cities. For the remainder of the century, with most of Europe and large parts of East Asia destroyed by the fighting, the United States entered a period in which it would enjoy military and economic influence over much of the globe. Yet, despite that consistent military superiority, the United States has not again celebrated the decisive end of a conflict in the manner it celebrated V-E day, 70 years ago.

Instead, the LIFE magazine images of American servicemen and women celebrating in Times Square have been replaced by the unfortunate memes of Vietnamese civilians clinging to the skids of American helicopters fleeing Saigon, and President George W. Bush’s premature declaration of “Mission Accomplished” from the flight deck of the U.S.S. Abraham Lincoln.  Tragically, America’s involvement in foreign conflicts since 1945 dependably circles back to the question, “How did we get here—again?”

In his recent book Before the First Shots are Fired, retired Gen. Tony Zinni blames America’s elected officials for dragging the country into conflicts without clear objectives, and for failing to provide the world’s most powerful military with the political leadership required to succeed in modern conflicts. The Washington elite ignores General Zinni at their own peril: After cutting his teeth training Vietnamese marines, Zinni went on to an illustrious 40-year military career, culminating with a stint as CENTCOM commander from 1997 to 2000. Since leaving the military, the general has held a number of positions from the classroom to the boardroom, in addition to serving as the US Envoy to Israel and the Palestinian Authority.

General Zinni’s primary argument in Before the First Shots are Fired is that while America’s soldiers are the best in the world, the nation’s political leaders who are responsible for providing and elucidating the casus belli upon entering wars, and negotiating the treaties to end them, are sadly inept. Politicians, he writes, choose to enter wars for political reasons, often based on politicized intelligence. Once boots are on the ground, these same politicians look for “measures of success,” such as enemy combatants killed and/or elections held, in order to justify the wisdom of their policies. But more often than not these decisions are made in Washington, far from the battlefield, and are based on domestic “political realities” instead of military ones: e.g. the 2009 “surge” in Afghanistan, the precipitous retreat from Iraq, and the ill-conceived “Arab Spring” season of support for overturning the political order from Libya to Egypt to Syria, just to name a few.

Zinni’s book is an insider’s account of America at war, both in Washington and in the battlefields of Vietnam, Afghanistan, and Iraq. It sketches out how the styles of successive presidents have impacted when—and how—we go to war.  Zinni gives a humbling example of Bush the “decider”, a Commander in Chief who preferred to avoid the details of analysis and planning.  In the run-up to the Iraq war, he explains, a set of war games named “Desert Crossing” were implemented to test the military’s readiness to face the challenges expected in the upcoming invasion. “The findings were astonishing,” writes Zinni. “Although we could easily win a battlefield victory over the regime’s armed forces … it was clear that we did not understand the source of far greater problems—the likely messy post-Saddam environment in Iraq.”

Before the First Shots Are Fired contains a great deal of wisdom from one of the preeminent military thinkers of our day. General Zinni argues that the United States cannot avoid a global leadership role. However, he stresses that the military must not be the singular tool in our nation’s national security toolbox: “Our foreign aid budget is pitiful, our State Department, USAID, and other critically-needed government agencies are underfunded, undermanned, and poorly structured for the tasks we need them to accomplish,” he cautions.

In the concluding pages, the author presents sobering advice on facing up to America’s current challenges. One recommendation that is repeated throughout the book is to “erase the board.” Referring to U.S. national security commitments in far-flung areas of the globe, the author argues that there is an imperative to re-evaluate the assumptions we have made in the past: “If [these commitments] are credible and warranted, then we should revalidate and keep them, but we shouldn’t assume the circumstances and justifications that were valid decades ago still obtain.”

Our soldiers, sailors, and airmen have shown they are ready and willing to sacrifice for the mission at hand. Before the next conflict is upon us, our political leadership would do well to heed the general’s advice.

Daniel Patrick Gabriel served as a CIA counter-terrorism officer in the Global War on Terrorism.