If asked, most Americans wouldn't say that Europe is going to be a big challenge for the next president, especially in comparison with the hotspots that splash across the headlines everyday.

Despite some deep-seated anti-Americanism in a few corners of Europe (stemming largely from the Iraq War), our nearly 500 million neighbors across the Pond seem to be peaceful and prosperous - for the most part.

Even so, Europe won't be a walk in the park for the next chief executive. Below the surface of that seeming quiet and contentment lies a plethora of problems that, regrettably, could affect American national interests significantly.

First, terrorism is still a huge concern. European capitals regularly report to Washington that they're finding new extremist networks, including some "homegrown" ones, in their Muslim communities.

The Germans and Turks disrupted terror attacks last year; Spain unraveled a plot against several European countries this year. Britain is following tens of terrorist plots, hundreds of terrorist cells and thousands of potential terrorists/sympathizers.

Unfortunately, al Qaeda and others who may be inspired by Osama bin Laden, but not under his direct operational control, continue to see Europe as both a target and a gateway to attacking America.

The foiled 2006 plot to bring down 10 or so US-bound airliners from Britain with liquid explosives is a good example of how terrorists might use Europe as a stepping stone for strikes against the American homeland.

Next, while the likelihood of a major war in Europe is thankfully about zero, if there were to be any conflict in Europe, it would likely flare up in the Balkans - as it has so many times before.

The issue of Kosovo's February declaration of independence from Serbia - after nearly a decade of UN and NATO stewardship following the Serbian army's attempted 1999 ethnic cleansing of local Albanians - is far from resolved.

To date, Serbia and its big-power backer, Russia, refuse to recognize the secession of the Albanian-dominated province. In fact, only about 35 countries of the 192 in the United Nations have recognized its independence so far.

Kosovar Serbs are considering their own break from Kosovo or joining back up with Serbia. Indeed, a Russian parliament committee recently recommended that Moscow recognize a new Kosovar Serb state.

The ethnically divided city of Mitrovica saw the worst violence since the split, when local Serb protestors battled UN police last week. Many are pointing the finger at Belgrade as the instigator.

Kosovo's split could also spark others to move toward independence. Bosnia, a fragile confederation of Serbs, Croats and Bosniaks (Bosnian Muslims) also could fly apart, leading to a return of 1990s-style ethnic violence.

Another challenge will be to keep the ball moving on missile defense in Europe, where public opinion is mixed. Fortunately, there's already been progress in negotiating the deployment of interceptors in Poland and a radar in the Czech Republic. Closing the deal and breaking ground for these facilities (which will take until 2013 or so to come online) will be critical in blunting the threat from Iran, given Tehran's continuing uranium enrichment and ballistic-missile development.

NATO is another key matter the next president will have to manage. The military alliance must maintain the will to fight and win in Afghanistan, including providing additional forces to the more than 40,000 US and NATO troops already battling the Taliban.

The next commander in chief must also encourage NATO members to spend more on defense so the organization stands ready when needed. (Most are spending less than the recommended 2 percent of their gross domestic product.)

While the French are likely to announce they're fully rejoining NATO this year at the April summit in Bucharest, there will be a quid pro quo. (French President Charles de Gaulle withdrew from NATO's integrated command in 1966.)

Even though France may add some additional troops to the NATO force in Afghanistan, Paris also wants a separate European Union (EU) defense force that parallels, and may eventually rival, NATO, undermining the alliance's political solidarity and military strength.

The French, of course, insist the EU force would improve NATO's potential punch, rather than undermine its unity or transatlantic ties with America. (Not everyone agrees, to say the least.)

Of course, getting the Europeans to spend more on defense, considering they now spend only 1.5 percent of GDP on average, will be a hard sell. Result? It's likely there'll be either sufficient resources for the EU force or NATO - but not both.

Even with the French providing 2,000 soldiers, the EU recently failed to find even 4,500 troops for a mission to Chad to provide relief for the dire situation across the border in Darfur in Sudan.

Working with Europe on dealing with Russia's re-emergence also will cause more headaches for transatlantic ties than cheap champagne. Unfortunately, not everyone agrees on how to handle the boisterous bear.

Moscow is cranky about missile defense, NATO expansion, Kosovo and any outside involvement in its "near abroad," especially Ukraine and Georgia. Lectures on "democracy" also annoy the Kremlin.

Not surprisingly, Moscow is working to divide Europe, NATO and the United States, using in-your-face diplomacy, petro-politics (parts of Europe are tres dependent on Russian natural gas) and saber-rattling as wedges.

In the end, working with Europe on local and global challenges makes sense, especially considering our shared democratic values; how to solve these problems, however, won't line up exactly.

Thankfully, transatlantic relations have improved greatly during President Bush's second term. The challenge for the next prez will be keeping them that way, while still protecting our national interests.