A Kings of War blog article laments the political attention given to foreign and security policy in the General Election campaign so far:
Whilst some people might look at the treatment of foreign policy, defence and security issues during the 2015 UK General Election campaign as a farce, is it not now becoming something much more akin to a tragedy?
Link:http://kingsofwar.org.uk/2015/04/cclkow-the-2-doctrine/

Sometimes the leaders refer to their opponents stance on the Trident dettterent, without mentioning the Scottish Nationalist's adamant opposition to its basing in Scotland. Fewer wonder as defence is not "ring-fenced" from spending cuts how much post-election defence will be cut.

I expect that the UK will end up spending less than 2% even after fudging the figures. What the UK spends does not IMHO affect other European nations; it may annoy the USA though.