KYIV, Ukraine (AP) — Russian President Vladimir Putin has ordered a partial mobilization of reservists in Russia, effective immediately. He risks a deeply unpopular step that follows humiliating setbacks for his troops nearly seven months after invading Ukraine. It’s the first mobilization in Russia since World War II. Western backers of Ukraine derided the move as an act of weakness. The Russian leader also warned the West he isn’t bluffing over using everything at his disposal to protect Russian territory, in what appeared to be a veiled reference to his nuclear arsenal. The partial mobilization came a day after Russian-occupied regions in eastern and southern Ukraine said they would hold votes on becoming part of Russia.