To give PMTM her due, this is a perfectly legitimate question to ask. A lot of the discussion within Defence, and amongst the defence-minded on places like here treats the idea of the UK as a Tier 1 military power as a given.
It's not. We live in a democracy, where the voters choose a government, and influence how much tax they pay, and how it is spent.
Many of them - most, I suspect - do not understand what a Tier 1 military power is, let alone why it matters that the UK is one. They want to know why the UK is spending billions on expensive pieces of military equipment when the NHS is struggling, school funding isn't being increased, the pension age is rising, and taxes are going to rise.
As has been the case for the last ten years, there is no money. The UK still has a substantial national debt - the interest on that debt costs about as much annually as the defence budget. The government is still running a deficit. An aging population needs more health care, and pensions.
Brexit will cost the government GBP 300m a week in tax revenues.
If politicians, and the armed forces, cannot explain in words of one syllable or less, why the public need to accept less of the things they want because it's important to have ships, planes, submarines and tanks, then bluntly there is no case to be a Tier 1 military power.
And given the points being made repeatedly on here and in other forums my the defence community about the challenges of trying to be a Tier 1 power on the cheap, what is the cost benefit analysis of finding more money to retain a status that will cost increasingly large amounts of cash?
What is self evident to you is not the same as being beyond doubt. Make a case.