Our values and defending them

This is being written in bits as I'm feeling very warm at the minute  and to be honest there are couple of things I could of blogged about this week but I'm choosing one that's topical and I think worth mulling over.
As much as I dislike 'soundbites' there was one on Thursday I felt worth looking at and it's from a 'marmite' politician where President Trump of the States said "The future of Western civilization is at stake" before stating the following question: "The fundamental question of our time is whether the West has the will to survive."
What he had in mind when it came to the threat was both political and religiously motivated terrorism and extremism that rejected liberal democratic values, such as free speech, free and fair elections, an independent justice system free from political and religious interference and the use of terrorism to bring those societies that support such principals within its orbit.
The is little denying groups such as Isis do explicitly reject what we call western values believing in a single World-wide Islamic state that is a Theocracy rather than a Democracy that operates to its interpretation of that religion and to which it alone runs justice to its own so-called Sharia Law standards.
The usual and mainly left-wing explanation of their terrorist inspired activities in the west is one of fighting the actions of Western Governments in conflicts that affect them such as in Syria and Iran and in recent past Iraq and Afghanistan by bring death and disruption to our streets. "If only we'd of left them alone" it is at least implied "we'd not of seen the recent incidents in London, Manchester and Paris".
I'm not a fan of such 'interventions' not least as they typical don't have a endplan in place but I do wonder if the aim isn't actually wider wanting to whatever means to transplant its ideology on our soil and us terror was a kind of warfare to remove political and legal obstacles at best giving them the upper hand when it comes to us looking after our own interests around the world?
There is a concern that once a parallel legal system is permitted even in a limited form, you erode the common stock of legal rights that are the birth right  all living and born in our society. We may cherish our diversity but what of it when elements of it such as the rights of women and lgbtqi rights it may in effect be denied to groups within it?
Just how much of our moral, cultural and liberal democratic values as a society should we be be prepared actively to keep from people who either don't share them or even wish to take them away?
This kind of conundrum is the very thing a society like ours, liberal and diverse needs to think about so while I don't hold much with the man, maybe it'll start a debate where we do arrive at a consensus around these questions.