So a deadly fungus, capable of wiping out roughly 30% of Britain's trees, is identified in a plant nursery. What does Defra do?
Does it destroy all the saplings in the batch, discover where they originated, trace all others imported in the same batch, destroy them and then halt all further imports?
Or does it do nothing for a few months and then hold a consultation?
This being Defra, the department incapable of making any snap judgements or quick, radical decisions, it did nothing before eventually going down the route of holding a consultation. And such things, as you will know, cannot be hurried.
First of all you have to draw up a list of potential consultees, which must be passed round and round and up and down the department for approval.
Then the detail of what they are actually being consulted about must be agreed before the letters can be sent out.
A certain amount of thumb-twiddling delay ensues before the replies come back, and the responses can be collated and summarised in a report.
So it was only in late October – a full eight months after the first discovery – that Defra Secretary Owen Paterson got round to banning all further imports of ash trees, as well as halting the movement of seedlings and saplings within our borders – a ban which will presently be drowned out by the whining of chainsaws as foresters make desperate attempts to halt the progress of Chalara fraxinea before millions of infected spores are released, creating the kind of arboreal carnage not seen since Dutch Elm disease.
Mr Paterson cannot be personally blamed for any of this. He has only been in the job a short while. But he could have the decency to admit Defra has cocked up yet again.
Because there is evidence here of the same appalling lack of urgency that has become the unfortunate hallmark of this unwieldy, overstuffed, monolithic department.
The barriers should have gone up immediately when a routine inspection found diseased trees, imported from Holland, at a nursery in Buckinghamshire in February. If not then, certainly in July, when 58,000 trees had to be felled on a Forestry Commission estate in Scotland and cases were also confirmed in Yorkshire and Surrey.
But Chalara fraxinea is not the only problem. At the other end of the country Phytophthora ramorum is making steady inroads in Japanese larch trees while worryingly spreading to other species.
Earlier and better surveillance by the Forestry Commission may be turning the tide – the area of infected trees needing to be felled is down to 435 hectares this year from 1,107 last year. But the damage and the cost have been considerable.
Though it must be acknowledged that some incidences of Chalara fraxinea may be due to airborne transmission of spores from Europe, both these cases illustrate the fact that we have an appallingly lax attitude to biosecurity when it comes to food and plant imports. And that simply has to stop.
We can do nothing about diseases that are blown here on the wind from the near continent. But we absolutely have to follow other countries' lead and install far tougher controls at our ports.
Since we are now importing so much of our food, we cannot – must not – sit back and allow customs officers to blithely wave through consignment after consignment of goods which could at any moment unleash some new and devastating epidemic.
Despite a token response when the threat was first pointed out to the Labour administration, bush-meat imports appear to be on the rise again. Are we importing eggs riddled with salmonella? Where are the controls?
I recently travelled to the USA and was not allowed to take so much as a dry biscuit through border control.
I had to sign a customs declaration to the effect that I had no food of any kind in my luggage, neither fruit, vegetables, meat, spices, nuts, grains or seeds, and then faced further questioning at the airport when I arrived.
Going up to Canada, the same applied with even more rigorous controls and inspections. And who can blame them, particularly when one considers the remarkable catalogue of animal diseases they have watched descending on Europe in recent decades?
Farmers have long since taken the view that Defra is simply not fit for purpose, and the debacle over the ash trees merely confirms that.
Never was there a better case for dismantling the entire structure and setting up a strong, core Ministry of Agriculture, not merely to service and support farmers but to protect this country from natural disasters such as the one now unfolding in slow motion before our eyes.