Here's the text in English:
A Spanish judge, acting under international law, will soon decide whether to investigate US officials' roles in authorizing torture. We hope you agree that such cases must go forward, despite pressure from the Obama administration to drop them. The organizations sponsoring this advertisement represent hundreds of thousands in the American public who believe the US government must be held to the same rule of law as other countries. We thank the people of Spain for your courage, and ask for your support as your courts consider bringing American officials to justice for the crime of torture.
http://warisacrime.org/content/american-human-rights-groups-place-ad-spanish-newspaper-encouraging-prosecution-us-war-crimi