Despite growing fears that the United States is losing the war on terrorism, President Bush has reclaimed the advantage over his Democratic challenger John F. Kerry as the candidate best able to deal with the international terrorist threat, according to the latest Washington Post poll.

The survey found that 55 percent of Americans approve of the way Bush is handling the campaign against terrorism, up five points in the past three weeks. Slightly more than half -- 51 percent -- also said they trust Bush more than Kerry to deal with terrorism, while 42 percent prefer the Democrat. Three weeks ago, the two were tied on this crucial voting issue.

But other results were less favorable for the president and underscored the growing unease with the war in Iraq and the state of the U.S.-led international war on terrorism.

For the first time in Post polls this year, less than half of the country -- 46 percent -- said the United States is winning the war on terrorism, down eight points since April.

At the same time, the proportion of the public who say the war with Iraq was not worth fighting has grown to 53 percent, a record high. A slight majority -- 53 percent -- say the conflict with Iraq has contributed to the long-term U.S. security.

Bush's overall job approval rating stood at 48 percent, unchanged from last month. Half disapproved of the job he was doing.

The survey also found that Kerry's choice of Sen. John Edwards (N.C.) as his running mate did little to change the overall character of the race. Although the Edwards selection was greeted warmly by many voters, particularly Democrats, Kerry and Bush remain in a tight battle -- with each candidate claiming 46 percent of the hypothetical vote of registered voters. In June, the Massachusetts senator led Bush 48 percent to 44 percent.

Nearly half of voters -- 47 percent -- said the selection of Edwards made them feel more favorable toward Kerry while 22 percent said they were less favorably inclined and 26 percent said it made no difference. That is a slightly less positive reaction than the one that greeted Bush's choice of Richard B. Cheney four years ago or the initial reaction to Al Gore's selection of Sen. Joseph I. Lieberman (Conn.).

On several key measures, Kerry has improved his standing with voters in recent weeks while Bush's image has eroded. Eight in 10 Kerry supporters -- 79 percent -- say they will "definitely" vote for him, up from 72 percent in three weeks; 76 percent of Bush's supporters are firmly behind their candidate, unchanged from last month.

At the same time, Kerry may be closing the perceptions gap separating him from Bush on some key measures of leadership and performance. A majority of the public -- 55 percent -- said Kerry is a "strong leader," up from 52 percent in April. Although slightly more Americans -- 59 percent -- see Bush as a strong leader, his standing has dropped five points since April and 15 points in the past year. Similarly, Kerry has cut Bush's double-digit advantage on which candidate could be trusted to handle a crisis to four points since May.

A total of 850 randomly selected adults were interviewed July 8 to 11. The margin of sampling error is plus or minus 3 percentage points.