Then there is the factor of taxation, or more precisely the presence
or absence of the need for it. No European monarchy has been a rentier
state—all have had to levy taxes, with all the pressures for cooperation
between crown and parliament that this implies. Of today’s eight Arab monarchies, by contrast, all save Jordan and Morocco are petrostates in
which oil money obviate the need to tax citizens while giving rulers ample
means to control society through subsidies and coercion. The need to
tax is a force favoring DPM that has been mostly absent in the Middle
East but long present in Europe. If they survived war and ethnic conflict,
European monarchies—with their taxation requirements and their lack of
large and politically potent royal families—became subject to pro-DPM
political pressures, as the Danish and Swedish cases illustrate.