Police officers guard one of the entrances to the Houses of Parliament in central London, Monday Oct. 4, 2010. Britain's Home Secretary Theresa May said that the threat of terrorism in the U.K. remains unchanged. Britain's Foreign Office has upgraded its travel advice for France and Germany, warning Britons going to those countries that the threat of terrorism there is high. (AP Photo/Lefteris Pitarakis)

There’s never a good time to issue a travel warning. But with Japan joining the U.S. and Britain in talking up a possible terrorist attack by al-Qaeda or other groups, how much of a profound effect is this likely to have on tourism?

Over the weekend, the U.S. State Department alert advised the hundreds of thousands of American citizens living or traveling in Europe to take more precaution. Britain’s Foreign Office warned those in or going to France and Germany that the terror threat was high.

But the business travelers and tourists arriving Monday at Paris’ Charles de Gaulle airport from the U.S. seemed in bullish mode. Speaking to the AP, people didn’t want the warnings to disrupt their plans.

“I’m very happy to be here in France. I think we’re very safe, and I trust the French government to keep us safe,” said James O’Connell, a 59-year-old from Pittsburgh, arriving in Paris for a 7-day vacation.