From January 1st 2018 a new fixed-price law comes into effect in the French-speaking part of Belgium, putting the region on par with France, Germany and the Netherlands in limiting the discounting options of retailers. The “other half” of Belgium is likely to follow suit in 2018.

The restriction applies equally to print and ebooks and allows just 5% discounting for trade titles for the first two years of publications (one year for comics), with slightly higher options available for libraries and schools (15% for general titles and 25% for textbooks).
The Belgium ebook market is estimated at around $290 million (the country has a population of only 11 million, of which some 5 million are French-speaking) and the new law, according to Culture Minister Alda Greoli, will “help maintain a large and varied number of sales outlets and a quality and diversified supply” of titles.
While not actually mentioning Amazon, Greoli went on, “countries that have no regulation or have abandoned it are faced by a concentration of distribution and creation that is damaging to cultural diversity.”
Belgium’s TRBF  is more blunt about it, asking,

Can the single price preserve the plurality of broadcast channels in the face of Amazon’s hegemony? Can the booksellers consider that they have won the game? Will publishers and authors also benefit from the single price?

Time will tell.
The law will also phase out the import mark-up that comes with French books in brought in from across the border in France, a hang-over from the pre- single currency days when exchange rates made imports from France more expensive.
The law will apply equally to books from self-publishers as from “Big Pub” and may be welcomed by Belgian indie authors putting their books up on Google Play, an ebook retailer notorious for discounting prices.