2013 International Day of the GirlBack in 2009-10, I spent a year embedded with the US military in southern Afghanistan. Something struck me right away: I rarely saw women, and on the few occasions I did, they were always covered from head to toe — even their eyes — by a light blue burka (leading me to refer to them as “the blue ghosts”). Even more significant, perhaps, I never heard any of those women speak a word.All local government officials were male. Women did not participate in government, business, or society at large. They took care of the home, raised children, and worked in the fields — sometimes literally as draft animals — yet they were social outsiders. Men made all important decisions. Girls as young as 11 were forced into marriages with much older men. Reports of domestic abuse — some cases so violent I still shudder when I think about them — were frequent.Afghanistan is one of the poorest countries on the planet, and Zabul, where I served, among its poorest provinces. It was also one of its most dangerous, being a source, refuge, and training ground for Taliban fighters. Even taking into account the lack of material resources and education in the province, I still could not help but wonder how different things might have been had half the society not been excluded from participating in society.That, of course, is what the International Day of the Girl, celebrated yesterday, is all about: promoting gender equality and investing in women and girls to promote prosperity, peace, and security. When girls thrive, nations thrive.Any number of studies show that the most competitive and prosperous countries are those where the gender gap is narrowest in a range of areas, including access to education, health, and economic and political participation. Countries progress economically, socially, and politically only when girls and women participate fully in all aspects of society and are protected from discrimination and other harmful activities such as early and forced marriage and gender-based violence.Despite that obvious truth, in too much of the world — not just Afghanistan — girls and women still do not have equal opportunity to reach their full potential. Two-thirds of the world’s illiterate are women. Thirty-nine million girls do not attend school.In many countries, girls and women receive inadequate health care and nutrition. In some places, girls are fed last and denied medical care simply because they are girls. An estimated 10 million girls are married every year before they reach the age of 18, and about 16 million girls aged 15 to 19 give birth every year, which is linked to maternal mortality and health risks, curtailed education, and limited economic opportunity.Through USAID and other agencies, the United States is working to ensure that girls in the developing world have opportunities to make the most of their lives and contribute to their communities.From 2009-2011, we helped 84 million girls go to school around the world. Our Safe Schools programme is working with teachers, administrators, students, and parents not only to strengthen girls’ academic and vocational skills, but also to make school environments free from gender-based violence and safer for girls. We work with local community organisations to persuade families not to force their school-age daughters into marriage. And we support efforts worldwide to prevent and address gender based-violence generally.This Day of the Girl gives us all — Americans, Bermudians, and others — an opportunity to consider these important issues and some of the ways we can work together to overcome the barriers that might keep girls and women — and their communities — from achieving their greatest potential.Bob Settje is the US Consul General.