Ukraine should be one of the most hopeful countries in Europe. It has the location, the transportation links, the farmland and factories and the eager population to become a post-Communist success story on the scale of its booming neighbour Poland.

Yet Ukraine is, as everyone can now see, a disaster. And, in good part, it is a disaster because Western governments allowed it to become one. The violence that has consumed the country emerges not from dissatisfaction with a leader – Ukrainians have endured a great many terrible leaders, and this is not a democracy protest – but from the country’s failure to end its crippling isolation from the world’s largest economy, the 28-nation bloc located across its high-security western border.