How should Europe respond to sovereign investors in its defence sector?

A small number of sovereign investors, sometimes originating from non-democratic states, are buying shares in European aerospace and defence companies. Some EU governments have responded by calling for tougher controls on foreign investment in their defence industries. Clara Marina O'Donnell argues that EU countries should not reject sovereign investors in principle. Instead, they should rely on investigative committees to assess the possible risks of sovereign and other foreign investments. And in the long term, EU member-states should co-ordinate their efforts.