Remember Yahoo and Google's short-lived advertising deal, which came about shortly after Microsoft's failed purchase attempt of the company?  Just when it seemed Microsoft and Yahoo were merged at the hip and going to ride off into the sunset together holding hands, along comes Google again looking to play the home-wrecker.

Google has scored a deal with Yahoo Japan to become the exclusive engine provider for the company's search.  Information from Yahoo's portal will be funneled directly to Google's network of sites, and the pair will cooperate closely on many efforts.

The deal is very significant as Yahoo Japan is the most used search engine in Japan.  It is perhaps inaccurate to call Yahoo Japan a part of Yahoo (U.S.).  The American search engine company owns one third of the Japanese firm.  It indicated that it would support its Japanese property, despite the fact that it picked Google's search engine over Bing -- Microsoft's search engine that power Yahoo's U.S. search portal.

Microsoft, though, is infuriated that Yahoo Japan has moved in with Google.  It say the deal likely violates antitrust laws.  It comments:

This agreement is even more anti-competitive than Google's deal with Yahoo in the United States and Canada that the Department of Justice found to be illegal. (The) deal would have locked up 90 percent of paid search advertising. This deal gives Google virtually 100 percent of all searches in Japan, both paid and unpaid. It means there will be no search competition in Japan and that Google will end up controlling all personal search information for all Japanese consumers and businesses.

Masahiro Inoue, Yahoo Japan President, however, said the decision was merely the best business move for his company.  He says that they evaluated Microsoft first, but among other considerations found its Japanese language search options to be sub-par.  Google delivered a much higher product, in his engineer's opinion.

The deal could prove a crucial one for Google's worldwide efforts, at a time when its facing the thorny task of mending broken ties with the world's largest population of internet users, China.  Its also a sign that the company's investment in foreign language support is about to pay off handsomely, and a warning sign that Microsoft would be wise to focus on such support if it does not want its long-floundering search efforts to fall further behind.