The British government has fired the starting pistol on discussions to leave the European Union. The publication of a white paper Feb. 2 outlined the principal aims of what the UK wants in its Brexit negotiations to leave the EU.

It does little to address the ongoing concerns of the aerospace and defense industry, and it is vague and detached from geopolitical realities. In short, it is a wish without a plan. Of course, there is nothing wrong with setting out goals. While the white paper claims Britain can negotiate from a position of strength, it fails to say what the UK may be forced to give up or the unintended consequences that could result. The reality is that many of these ambitions cannot be delivered—at least not on the timescales that will prevent damage to the country’s aerospace and airline industries.

Worker at Roll-Royce engine factory-Berlin

Britain’s aerospace and defense industry was a fervent proponent of remaining in the EU. The European Single Market—the system closely aligned to the EU that allows tariff-free trade and the free movement of a skilled workforce—has been invaluable to the growth of the sector in the UK. Now, these two critical pillars look set to disappear.

But London has signaled that it will not seek membership in the Single Market, post-Brexit. Instead, it will pursue a “partnership” with the EU and a free-trade and customs agreement.

We fear that what all this means is that industry can also kiss goodbye the free movement of EU workers and the frictionless movement of aerospace components within Western Europe.

In theory, it should be easy to reestablish trade agreements between the UK and the EU. After all, both are closely tied economically. But in practice, it will likely take years to resolve. The mere promise of a new, stable, predictable regulatory regime that cuts out red tape may not be enough to keep investments flowing.

What is more, questions remain over access to European funding for research and development and to regulatory agencies such as the European Aviation Safety Agency, entry to which is deemed critical by British aerospace. The UK government’s response is sketchy at best; London has stated only that it will discuss membership in these bodies.

An optimistic British minister in favor of exiting the EU, David Davis, told Parliament that the “best days are still to come.” But even with all the good will in the world, achieving Britain’s ambitions in full and satisfying the needs of its most important industrial sectors could take decades.