Today marks the 16th anniversary of Al Qaeda’s 9/11 attacks. We learned much on that tragic day, at enormous human and material cost. Perilously, however, America has already forgotten many of September 11’s lessons.

The radical Islamicist ideology manifested that day has neither receded nor “moderated,” as many naive Westerners predicted. Neither has the ideology’s hatred for America receded, nor its inclination to conduct terrorist attacks. Iran’s 1979 Islamic Revolution brought radical Islam to the contemporary world’s attention, and Iran is no less malevolent today than when it seized our Tehran embassy, holding US diplomats hostage for 444 days.

The Taliban, which provided Al Qaeda sanctuary to prepare for the 9/11 attacks, now threatens to retake control in Afghanistan. Al Qaeda persists, and may even be growing worldwide.

While ISIS’ caliphate in Syria and Iraq will not survive much longer, countries across North Africa and the Middle East (“MENA”) have destabilized or fractured entirely. Syria and Iraq have ceased to exist functionally, and Libya, Somalia and Yemen have descended into chaos. Pakistan, an unstable nuclear-weapons state, could fall to radicals under many easily predictable scenarios.

The terrorist threat is compounded by nuclear proliferation. Pakistan has scores of nuclear weapons, and Iran’s program continues unhindered. North Korea has now conducted its sixth — and likely thermonuclear — nuclear test, and its ballistic missiles are near being able to hit targets across the continental United States. Pyongyang leads the rogue’s gallery of would-be nuclear powers, and is perfectly capable of selling its technologies and weapons to anyone with hard currency.

During Barack Obama’s presidency, he ignored these growing threats and disparaged those who warned against them. His legacy is terrorist attacks throughout Europe and America, and a blindness to the threat that encouraged Europe to accept a huge influx of economic migrants from the MENA region, whose numbers included potentially thousands of already-committed terrorists.

Obama also ignored North Korea, affording it one of an aspiring nuclear proliferator’s most precious assets: time. Time is what a nuclear state needs to master the complex scientific and technological problems that it must overcome to create even more nuclear weapons.

And, in a dangerous unforced error that could be considered perfidious if it weren’t so foolish, Obama entered the 2015 Vienna nuclear and missile deal that has legitimized Tehran’s terrorist government, released well over a hundred billion dollars of frozen assets and dissolved international economic sanctions. Iran has responded by extending its presence in the Middle East as ISIS had receded; it now has tens of thousands of troops in Syria and is building missile factories there and in Lebanon.

Before 2009, publishers would have immediately dismissed novelists who brought them such a plainly unrealistic plot. Today, however, it qualifies as history, not fantasy. This is the agonizing legacy that the Trump administration inherited, compounded by widespread feelings among the American people that we have once again sacrificed American lives and treasure overseas for precious little in return.

These feelings are understandable, but it would be dangerous to succumb to them. We didn’t ask for the responsibility of stopping nuclear proliferation or terrorism, but we are nonetheless ultimately the most at risk from both of these threats.

And as we knew during the Cold War, but seem to have forgotten since it ended, our surrounding oceans do not insulate us from the risk of long-distance nuclear attacks. We face the choice of fighting the terrorists on our borders or inside America itself, or fighting them where they seek to plot our demise: in the barren mountains of Afghanistan, in the MENA deserts and elsewhere.

Nor can we shelter behind a robust national missile-defense capability, hoping simply to shoot down missiles from the likes of North Korea and Iran before they hit their targets. We do not have a robust national missile defense capability, which is partly due to Barack Obama’s drastic budget cuts.

President Trump appreciates that nuclear proliferation and radical Islamic terrorism are existential threats for the United States and its allies. During the 2016 campaign, he repeatedly stressed his view that others should play a larger role in defeating these dangerous forces, bearing their fair share of the burden. But candidate Trump also unambiguously (and entirely correctly) called for restoring our depleted military capabilities, because he saw that American safety depended fundamentally on American strength.

September 11 should be more than just a few moments of silence to remember the Twin Towers falling, the burning Pentagon and the inspiring heroism of regular Americans in bringing down United Flight 93 in Shanksville, Pennsylvania. We should also seriously consider today’s global threats. Those who made America an exceptional country did so by confronting reality and overcoming it, not by ignoring it.

John Bolton, a senior fellow at the American Enterprise Institute, was the US permanent representative to the United Nations and, previously, the undersecretary of state for arms control and international security.

This article was originally published by the Pittsburgh Tribune-Review.

The opinions presented by Algemeiner bloggers are solely theirs and do not represent those of The Algemeiner, its publishers or editors. If you would like to share your views with a blog post on The Algemeiner, please be in touch through our Contact page.