Prior to the Nazi/Soviet carving up of Poland, Euro-states responding in three different fashion to the dictator threatening the false peace of Europe, some were in the final stages of formulating open collaboration, while others it was blatant, cowardly appeasement and one of little country was forced into surrendering, since the others did nothing to prevent the dictator's brute force.
In terms of Europe and the present Iranian threat. If their nonresponse to removing Saddam (due to the oil & payoff scandal) we can expect more statements, maybe a few half hearted sanctions, but when it comes to tangibly assisting in bringing down the Iran's Islamofascists, with (Western) E.U. continental troops, and attacking air power - forget-about-it...(unless Tehran's jihadist outcasts nuke a few cities first, and even at that those would require being in the heart of a major western E.U. nation before they lift a finger.)
I do believe the London shall join with Jerusalem and Washington, coupled with various types of support from some of our current allies in Iraq, and a few others serving in Afghanistan. Some of this will be made public while others will be hush hush due to numerous vulnerabilities.