The poor U.S. standing on international tests is a product of unequal access to the kind of intellectually challenging learning they measure. While other nations have been expanding educational access to more and more of their people and revising curricula, instruction, and assessments to support the more complex knowledge and skills, the U.S. has been turning its attention to standardized testing. Although some of America's schools are among the best in the world, the U.S. needs to create systems that guarantee all the elements of educational investment to all children. As in high- and equitably-achieving nations, this would require strong investments in children's welfare; high-quality preschool; equitably funded schools; a system that ensures that teachers and leaders in every community are extremely well prepared and are well supported; standards, curricula, and assessments focused on 21st century learning goals; and schools organized for in-depth student and teacher learning and equipped to address children's social needs. (Contains 3 endnotes.)