Today’s new terror warnings make clear that while the United States has avoided potential disasters that many foresaw in the ten years since the September 11 attacks, America remains profoundly challenged both by the threat of terrorism and in how we respond to that threat. Thus while a sense of satisfaction is warranted—and Presidents Bush and Obama deserve real credit for helping the country through a very difficult time—Americans can ill-afford either complacency or recklessness as we move forward.

The first and most important disaster averted lies in the fact that there have been no further major terrorist attacks on American soil—something it was difficult to imagine for those of us who were in Washington and New York that terrible day in 2001. This cannot be separated from crippling U.S. action against al-Qaeda’s central operations in Afghanistan and Pakistan, where the group no longer has a safe haven. A decade removed from September 11, it can be easy to take this success against al-Qaeda and our relative security at home for granted—but we cannot and should not. Preventing major new terrorist attacks in the United States did not just happen; it was the result of a substantial and sustained effort by senior officials in the Bush and Obama administrations, American military forces, and thousands upon thousands of security personnel, analysts and others nationwide. Other countries, including Britain and Spain, have not been so fortunate.

Second, and also quite significantly, the United States did not become a garrison state or, alternatively, produce a domestic “clash of civilizations.” The media, nongovernmental organizations, concerned officials and others exposed, blocked and reversed serious infringement of American liberty. At the same time—notwithstanding an uncomfortable environment for some American Muslims and isolated small-scale terror plots—the U.S. tradition of tolerance and acceptance has generally prevailed. This is testimony to the resilience of America’s political culture and society and to the strength of its values.

Third, despite assertive U.S. foreign-policy conduct—including military action in Iraq without United Nations Security Council support and in Libya well beyond the scope of what some major powers in the Security Council thought they had accepted—Washington has managed to avoid provoking the formation of a significant and sustained anti-American coalition. These fears peaked in the mid-2000s, when America’s poorly implemented and poorly understood efforts at democracy-promotion provoked widespread anxiety, particularly in China and a then-swaggering and oil-rich Russia.

These three accomplishments are real and quite important. Yet they do not tell the whole story of the last ten years—and America faces many new and serious challenges.

Even as the United States has cut off the head of al-Qaeda in Afghanistan and Pakistan, new heads have risen in conflict zones or other unstable areas around the world, including al-Qaeda in Iraq—which substantially complicated the U.S. war there—and al-Qaeda in the Arabian Peninsula, now widely considered among the greatest terrorist threats to Americans and American interests. To use a different metaphor, al-Qaeda has metastasized, and the original tumor is now perhaps less dangerous than those which have followed.

Moreover, while avoiding a garrison state and deep social conflict, the United States has in many respects adopted a damaging national security mindset. Domestically, this has led to the substantial expansion of domestic surveillance and database-driven security programs devoid of human judgment and turned air travel into a world of routine and demeaning searches populated by airline personnel who often act more like prison guards than customer-service agents. Meanwhile, the politically correct refusal to consider profiling or other successful intelligence-based techniques adopted in Israel and elsewhere combines with incompetent and uncreative management to produce security procedures that sometimes appear intended to create the appearance of security rather than security itself; the result is a widespread attack our liberty and our convenience.

This national-security mindset has had international implications as well. In defense and foreign-policy matters, it has led some to believe that America should spare no expense in promoting democratic values and in advancing national interests that are constantly expanding without clear limits. Few questioned the costs of a fundamentally optional trillion-dollar war in Iraq. Only now have many begun to wonder how the United States can justify continuing to spend over $100 billion per year in Afghanistan, a nation with a gross domestic product under $16 billion in 2010, after a decade of war. And even with U.S. forces still deployed in both of these countries, some called for massive American intervention in Libya.

Internationally, the combination of three wars in ten years with a serious domestic economic crisis has washed away post-9/11 sympathy and replaced it with disappointment, frustration and in some cases resentment of an America now often seen as a bully in decline. Vice President Joe Biden wrote in The New York Times that China’s leaders do not see America in descent, but if this is so the Chinese scholars one of us encountered in Beijing shortly after Mr. Biden’s visit there have not gotten the memo. Nor is this view limited to China.

What is most important for Americans in looking back at September 11 is that we refuse to allow today’s world to become the new normalcy. Domestically, Americans should have zero tolerance for abuses of civil liberties that do not actually add meaningfully to our security; to do otherwise is to allow further movement down a slippery slope. This should include public accountability in the media and in Congress for officials and executives who implement fundamentally un-American government or corporate policies under the pretense of security needs. In particular, top officials in the Transportation Security Administration should understand that Americans will not indefinitely tolerate excuses such as poor training or a reluctance to offend particular groups. TSA’s tendency to subject law-abiding travelers to senseless and insensitive procedures should likewise come to an end.

Internationally, the United States must become much more selective in its use of military force by adopting clear, national interest-based criteria for military interventions. Neoconservatives and their liberal interventionist fellow travelers routinely decry foreign policy restraint as “isolationism” and perversely equate warfare and constantly expanding defense budgets with international leadership. In fact, they are the isolationists; their blind ambition to remake the world isolates the United States and undermines its ability to lead.

A policy of restraint—combined with a willingness to do what it takes when really necessary—is the surest course to international leadership. It allows America to stand tall and to protect truly vital interests while generally focusing on domestic growth and preserving U.S. military strength and political leverage for the situations that really matter. Whatever some may think, the United States cannot be an effective global leader with a divided society, a ruined economy, a hollow military and a tattered reputation.