The UK bet its future on being open to trade generations ago, and this has intensified as the UK's economy has been engineered into a focus on services rather than manufacturing; so when supply chains are disrupted prices rise & supplies are constrained.
The US/Israeli attack(s) on Iran are now having a wide range of disruptive effects as we know, but the latest to be identified as a potential problem is medicines.... that might be pretty serious!
While surely the war is stressing the supply chain, the UK by design is always weeks away from shortages of one kind or another. The UK's is not a self-sufficient society in any shape or form. Likewise for most if not all Western countries.
The shock to me was when the UK voted for Brexit when 50% of its food – I mean, its FOOD – came from the EU. How far can manipulation go to make people not know where and how their food comes from, and to then vote against their very own interests.
There are good reasons why, e.g., France heavily subsidises its farmers.
Yes, its certainly true that many countries are highly dependent on imports, although the UK is perhaps more so... this is often celebrated as the UK being a particularly 'open' economy, but as you rightly say has put food security at the mercy of supply chains being stable & sustainable, which as we are finding out is not always the case....
Emeritus Prof Christopher May
Albert Cardona