A trade deal benefits both sides - both sides benefit from reduced tariffs and perhaps reduced non-tariff barriers on goods that fall in the various categories negotiated.
Yes, that's true about a trade deal but remember that the relationship that the UK currently has with the EU (and the relationship repeatedly promised by the Leave campaign) goes far beyond a trade deal.
The focus to date in the media has been on fishing, agriculture and manufacturing - goods in other words. This accounts for around 20% of the UK economy.
The deal should be symmetrical with neither side having to 'give' more than the other. To emphasize this point I reflect your question back at you and ask, "What do you think the EU is prepared to give, in order to secure a trade deal with the UK?"
So far the position adopted by the hard Brexiteers - and now seemingly endorsed by Boris Johnson is that the UK should get all of the benefits of EU membership without any of the responsibilities.
The EU has shown that it has various compromise positions:
- The UK could have most of the benefits of EU membership if it's willing to accept most of the responsibilities - EEA membership
- The UK can have many of the benefits, if it's willing to have many of the responsibilities - Customs Union membership
- The UK can have a few of the benefits of EU membership if it has a few of the responsibilities - Theresa May's or any other trade deal
The problem appears to be that the UK is unwilling to accept any of the responsibilities and thinks that reducing its demands a little represents compromise.
If the deal benefits both parties, why would you expect one party to have to 'give' something in order to agree it
I suppose it depends on what your starting point is.
If the UK and EU were currently trading on WTO terms then a basic trade deal would indeed be an economic benefit to both parties and, after a decade or so of wrangling would probably come up with something which covers most of the trade in goods.
That same trade deal compared to the current relationship between the UK and EU would be a significantly worse deal.
Boris Johnson't current negotiating position is that he wants more benefits for less in the way of responsibilities - sounds like hes asking the EU to make all the compromises.
As to your second question, there's never a guarantee that future events or a future government won't change an agreed deal. The EU could also change its mind after a few years and 'bin' any agreed deal. One can only hope that as long as the deal remains beneficial for both sides, then future rulers on both sides will continue to honour the deal.
The difference in this case is that Boris Johnson and his party are on record suggesting that reneging on the deal is a good idea. Hardly a recipe for good faith negotiation.