Moreover, as long as national authorities are responsible for bearing the costs of crises, they will be inclined to keep resources within their borders, or ring-fence them, which in turn will undermine cross-border financial integration.
But also economically, the crisis demonstrated beyond a doubt how costly and difficult it is for national governments to manage banking crises that are ultimately international in origin and often beyond their control. Pooling of resources at European level to deal with the failure of cross-border and of significant banks is much more efficient.