Fight those who do not believe in Allah ( i.e. Non-Muslims) , nor in the latter day, nor do they prohibit what Allah and His Messenger have prohibited, nor follow the religion of truth (i.e. Islam), out of those who have been given the Book ( including Christians and Jews ), until they pay the tax in acknowledgment of superiority (of Islam and Muslims) and they are in a state of subjection.
(Koranic Verse: 9.29; SOURCE)
Earlier Muslims covered the cross on the church with gunny bags ( here ).
But Sharia has to be enforced completely and every Non-Muslim has to abide by it; it is only then that Muslims are at peace. It is only then that Muslims feel that there is no aggression on them. Because mere presence of disbelief in Islam becomes aggression (Koran says this in verses 2:193 and 8:39) on Islam and Muslims. Now one can see how, when Muslims say their wars are always fought in defense.
One can read completely about Jizya from HERE .
Further Vandalism of Orthodox Church in Tunis ( here and here (this is in french) )
Non-Muslim places of worship are being targeted by still-unidentified individuals. After the attacks perpetrated against the Orthodox church on Avenue Mohamed V, the Russian school located behind the church as well as the Christian cemetery of Montplasir in Tunis have been vandalized.
The walls of the school were smeared with fecal matter, as also a fresco of Saint Siberian [sic] located in the back courtyard of the Orthodox church, while the cemetery's crosses were destroyed.
Yamina Thabet, the president of the Tunisian Society for Aid to Minorities (ATSM), indicated during a conference held April 4, 2012 at the headquarters of the National Union of Tunisian Journalists that the government is responsible for the protection of minorities in Tunisia, a protection that is imperative in the face of these repeated assaults. She especially lamented the government's manifest indifference with regard to minorities' right to protection.
According to the newspaper Le Maghreb, a Salafist burst into the church during April to deliver a letter from an Islamist party called "Hizb Allah" [not to be confused with the Lebanese party of the same name], inviting the archpriest to convert to Islam or to take down his church's crosses and pay the "jizya", a tribute that non-Muslims were required to pay at the beginning of the Islamic era [and oftentimes since then].
We note as well that the prosecutor of the Republic has ordered, Thursday April 5, an investigation to be opened within the context of the complaint filed by the ATSM regarding the calls made to kill Jews, according to the declaration of Ms. Thabet Thursday on Mosaïque FM.