PARIS (AP) — When Vladimir Putin congratulated Emmanuel Macron on his re-election as France's president and wished him "success in your activities," the Russian leader probably was being more polite than sincere.

As he embarks on a second term, with the intention of keeping France at the forefront of international efforts to force Putin to change course in Ukraine, Macron has given a green light for the delivery of modern artillery pieces to Kyiv that could help stem Russia's new offensive in the east of the country.

Firing six rounds per minute over 40 kilometers (25 miles) or more, the truck...