>>Trolls crack in the light<< -- Swedish proverb
Corporate patent lawyers and lawyers in general wield great influence in the United States. One Japanese book is titled "Litigating a Country to Death -- The United States of America". Like in Britain, the patent system ran out of control rather early in the US. In the 80s, this was partially reinterpreted as an american national "pro-patent" policy by which Japan and east-asian tiger states could be kept at bay.
The US has been and is allowing patent lawyers to determine its policy in multilateral rounds such as WIPO as well as in bilateral negotiations. These patent lawyers have, without much regard for US national interest, been using the muscle of the US government in order to press other countries into allowing patentability of everything under the sun according to US standards. At WIPO, the US is pushing for a Substantive Patent Law Treaty (SPLT) which rules out any limitation on subject matter and threatening to walk out if this is not achieved.
Be it WIPO, WTO or OECD, wherever unlimited patentability is not the target, the US delegation boycotts the work and instead relies on bilateral muscle-flexing. Jordan signed a bilateral agreement with the US in this sense in 2000. Japan was heavily lobbied and followed in every detail, even to extent of passing a law that obliges Japan to push for software and business method patents worldwide. US pressure has made itself felt in Europe, so that many, including French president Chirac, have spoken about a strategic need to resist the US pressure.
Whether this US pressure is really based on US national interest may be doubted. But without doubt the USA is in the position of the early adopter of software patentability. While others were still not taking the (illegal) expansionism of their local patent offices seriously, software patents became -- very much against the will of most US software businesses -- firmly entrenched in the USA, leaving US companies no choice but to adapt. About 2/3 of the European (illegal) software patents are in US hands, and many at the US companies (and at some large european companies who are active in the US market) would like to be able to leverage their assets in Europe also.