I think the problem with that though is that Parliament really doesn't know, in the main, what it is backing. On the most simple level - UK support for a friendly nation that has been attacked - they have been asked and are in favour (as many people are), but when it comes to the real detail of what is actually happening, what the government are actually doing, why they are doing (or not doing) it and whether it is effective they are not being asked (and the vast majority of them probably lack the experience to understand what the problems would be and ask the right questions anyway).
I mean take defence spending for example; not only we now face a much more serious security situation in Eastern Europe, to the oceans around the UK and globally we are also engaged in supplying the Ukrainians with sizeable quantities of military aid which is currently being met from stockpiles. The government haven't given any indication they are ramping up munitions production to restore those stockpiles, or lay in more for our own use, nor are they increasing the capacity to produce more in the future, nor are they reversing the 2021 defence review and its cuts even though it has been proved obviously wrong by events. We are nearly six months into the war at this point and we stand out noticeably amongst our NATO allies in that respect, most of whom are revamping their armed forces.
In the mid-1930s there were plenty of MPs with military experience who were able to warn of what would be required in the event of a big war, and managed to (just) get things in place. Yet the current lot are serenely failing to do anything, just as they are failing to do anything about all manner of crises afflicting us at present. I am not sure why, after looking into what we are doing now, anyone should support what we are doing beyond that simplest level of we are doing something.