The notion that the “future is female” has finally reached the military.

With the appointment of Sylvie Goulard as France’s new defense minister last week, four of seven G7 countries now boast women in a role long seen as a bastion of male power. These female defense ministers—which include Germany’s Ursula von der Leyen, Italy’s Roberta Pinotti, and Japan’s Tomomi Inada—lead armed forces with a combined expenditure of $170 billion.

While the combined military budget of G7’s female defense ministers is substantial, it’s still overshadowed by the world’s biggest armed force—America’s military expenditure totaled $611 billion in 2016. But the transition from all male to female-run militaries has been remarkably swift.

Until 2002, Finland was the only country in the Western world to have a female defense minister, according to Politico (Finland’s Elisabeth Rehn became the West’s first defense minister in 1990). Norway followed suit in 2000, followed by Sweden and France in 2002. A photo of Spain’s newly appointed female defense minister, Carme Chacón, patrolling a military base in Lebanon pregnant in 2008 became an iconic symbol of progress for women in defense. Since then, 18 countries in the EU have had female defense ministers (Sweden three times and Norway five).

The EU is currently chock full of female defense ministers—four of its five largest economies now have women in the role. But it was Sri Lanka’s Sirimavo Bandaranaike and India’s Indira Gandhi who first broke the mould by becoming heads of states (and by default heads of defense) in the 1970s. Since then, over 40 countries have followed suit in appointing female heads of defense, according to one comprehensive study (pdf) published last year.

Women were most likely to become defense ministers in countries that had become less conflict-oriented. In fact, some argue that women’s ascent in defense may have less to do with breaking the glass ceiling, and more to do with the diminished role of defense ministries in the post-cold-war era, as army sizes have shrunk.

Women have yet to permeate the world’s top military roles. Of the three G7 militaries currently run by men, no woman has ever headed up defense in the US or UK, while Canada had a woman in the role 1993, but not since. The countries with the second and third largest military budgets, Russia and China, are also still men-only.