As a free trader I think it is usually a good idea to specialise and then to buy in the goods and services you do not produce yourself. All individuals practise this, relying on the supermarket for our food and the power company for our electricity. They are better at those, with economies of scale, whilst we earn a living as best we can.
It can be true for many things for a nation . There are, however, some obvious limits. It would not be a good idea to rely for your defence on importing war supplies when you need them from countries that may be on a different side in a conflict. It is probably a good idea to produce enough food at home so we do not starve should there be some major disruption of global trade.
The UK needs to reassess its national resilience and ask if it has become too dependent on the goodwill of foreigners to supply many of the things we need. Some things ought to be easier to supply from local sources. Water, quarried stone, many other building materials, timber and energy are heavy and expensive to move around, so going more local could make economic sense.
How would you arrange our affairs so we have more of the essential capabilities and technologies an advanced nation needs?
I have written to the government proposing an energy policy that puts self sufficiency at its core. I will take up the issue of more home grown trees leading to more home grown timber, as the government is already committed to the costs of more trees. We need to turn this into a sustainable resource cutting the need to import substantially.
Importing bottled water looks like a bad idea environmentally as well as Economically, so where are the U.K. entrepreneurs who can win the battle of the bottled waters?
The U.K. government controls a lot of economic activity which gives it power as a buyer to organise competitive procurement that can stimulate U.K. activity in the chosen areas. It needs to learn from the NHS experience with procuring protective clothing, drugs, and medical equipment in the pandemic. It can doubtless improve on its experience then. It relied too much on possible foreign supplies which let it down, and ended up paying expensively for more domestic output in a hurry. Longer term planning and working with suppliers who can match world prices for sustained orders is required.