United States在此为何不用冠词the?

有人问: 我曾在China Daily上看到这样一句话:

A diplomatic effort was launched by United States and United Nations envoys after Lebanon broke off the talks to protest against the arrest of four Shi'ite Muslim leaders by Israel's army in south Lebanon.

为什么United States 前面不用冠词the,请答复。

我们谈到用作名词的“美国”时,一般须说the United States,前面须有定冠词the,因为它含有普通名词states。 “联合国”亦然,因为它含有普通名词nations,但当“美国”或“联合国”用作形容词时,则可用the,亦可不用the。如有所特指,仍须用the,如非特指,则不用the。句中的United States and United Nations envoys非特指,只说是一些“美国和联合国的特使”,故前面没有the。如果说the United States and United Nations envoys,那就专指某些美国和联合国特使而言了。你如果把United States换作形容词American,特指用the American envoys,非特指用American envoys, 即更容易理解为什么United States前可以不用定冠词the了。但请注意,如将用United States用作名词所有格,则仍必须用定冠词the,如the United States' envoys。