During her tenure as parliamentarian, Schuster has been particularly vocal about the importance of adhering to the international human rights treaties and has repeatedly coauthored parliamentary motions condemning human rights abuses in Russia, Belarus, and Iran, among others. Along with Bernard Kouchner and Bill Richardson, Schuster was among the signatories of an open letter to Russian presidentDmitry Medvedev, published on December 14, 2010 in the Financial Times, urging him to end the persecution of Mikhail Khodorkovsky and Platon Lebedev as well as to find justice for Sergey Magnitsky, Anna Politkovskaya, Natalya Estemirova, Stanislav Markelov, among others. In 2012, she joined the Justice for Sergei Magnitsky Interparliamentary Group, an international network including parliamentarians from Britain, Canada, Estonia, Germany, Italy, Norway, the Netherlands, Spain and Sweden. In the discussion on a European version of the Magnitsky Act, Schuster believes that "targeted travel sanctions against officials who are proven to have played a role" could be helpful if the Magnitsky case remains unresolved. On various occasions, Schuster has publicly denounced prominent cases of political prisoners, including former Belarus presidential candidateAndrei Sannikov; Russian punk-rock band Pussy Riot; Turkish pianist and composer Fazıl Say; and Ukrainian politicians Heorhiy Filipchuk, Yuriy Lutsenko, and Yulia Tymoshenko. Schuster supports same-sex marriage and has in the past voiced criticism against countries that fail to sufficiently protect their LGBT communities, such as in Uganda, Cameroon, and Russia. Under the umbrella of the German parliaments’ godparenthood program for human rights activists, Schuster has been raising awareness for the work of persecuted Zimbabwean activists Jestina Mukoko, Jenni Williams, and Farai Maguwu since 2011. Also in 2011, she took on a prisoner’s godparenthood for Belarusian youth activist Pavel Vinahradau.
Africa
Schuster’s views on the relationship between Europe and Africa reflect her party’s critical stance toward traditional development aid as a means of sustainable growth. She opposes budget support to African governments and favors unfettered access by African exports to the European market. Schuster aims at improving ties with the African Union. She has in the past voted for United Nations peacekeeping missions on the continent as well as increased support measures regarding police and military training in order to help African efforts to build up their own security structures, such as in Somalia, Sudan, Darfur/Sudan, Democratic Republic of Congo, South Sudan, and Mali. She was one of the initiators of the German government’s coordinated concept for African policies with a focus on topics rather than on regions.
Arms control
Schuster has been supportive of the Control Arms Campaign's efforts to create an Arms Trade Treaty as well as of Handicap International's fight against land mine. She supported the move by Germany and other nations to place disarmament high in the strategic concept agreed upon during NATO's 2010 Lisbon summit.