Sentence:  Seeing the British establishment struggle with the financial sector is like watching an alcoholic [...].  Until 2008 there was denial over what finance had become. [...]  But the scandals kept coming, [...]. A broad section of the political class now recognises the need for change but remains unable to see the necessity of a <WSD>fundamental</WSD> overhaul. Instead it offers fixes and patches. 
Meaning of the word marked with <WSD> tags:  Essential, as an element, principle, or law; important; original; elementary.