Geoffrey Bruun 'Europe and the French Imperium' 1938

'...the domaine extraordinaire, which was built up from the indemnities and confiscations inflicted upon vanquished foes. These contributions have been estimated at a thousand million francs for the years 1806-1810 alone. Napoleon drew on the fund for a variety of disbursements, for the maintenance of the army while in the field, the expenses of the imperial household, occasional subsidies for public works or special services. ............
Deprived of these receipts from abroad, it his highly improbable that the imperial government could have undertaken its program of public works without floating long-term loans.....'
And a little later in the same section:
'For even with the contributions from abroad swelling the war chest, military needs devoured over half the national revenues in years of peace. To undertake foreign ventures which would transfer the cost of supporting the army divisions onto alien shoulders and at the same time augment the war indemnities remained a perpetual temptation. For the Empire peace was an extravagance, and it is not without significance that the two most serious business depressions which struck France in this era - that of 1804-1805 and 1810-1811 - followed on the two intervals when the nation had been at peace for over a year.'

I'm sure the figures can be disputed, because figures always can be, but it's a strong argument.

Susan