The two countries merged into one.

这两个国家合二为一了。

《柯林斯英汉双解大词典》

Trade between the two countries has increased.

两国之间的贸易增长了。

《牛津词典》

The two countries have severed all diplomatic links.

两国断绝了一切外交关系。

《牛津词典》

With the coming of Mexican independence, the Santa Fe Trail became the major trade link between the two countries.

VOA: special.2009.03.30

It's been a troubled relationship ever since... the...you know, the emergence of the two countries.

早在这两个国家。,刚刚出现时,它们的关系就很糟糕。

普林斯顿公开课 - 国际座谈会课程节选

Quickly, India and Pakistan, ? How do they get along? Has the prospects for war between the two countries we see is in the background? -Probably yes.

印度和巴基斯坦，它们的关系怎么样,这两个国家间潜在的战争,可能爆发吗？，-也许吧。

普林斯顿公开课 - 国际座谈会课程节选

Diplomatic and trade relations between the two countries now ride on the fate of the extradition bill.

ECONOMIST: Colombia contemplates extraditing its drugsters

Venezuela's foreign minister said the meeting would "derail" good relations between the two countries.

BBC: Venezuela and Colombia in row over Capriles meeting

Relations between the two countries have been strained, most recently over the conflict in Syria.

BBC: Russia reveals Moscow CIA station chief's identity