What is the Khilafah?
The Caliphate as is termed in English is central to islam and an absolute basic necessity.
1. What is Dar al-Islam?
Dar al-Islam is the land where Islamic Law is implemented in all matters of life and ruling and whose security is maintained in the name of Islam even if its citizens are non-Muslims.
2. What is Dar al-Kufr?
Dar al-Kufr is the land where Kufr laws are implemented in matters of life and whose security is maintained in the name of Kufr even if all its citizens are Muslims. This is because the criterion of a region being Dar al-Islam or Dar al-Kufr are the laws that are implemented there, and the security by which it is protected, the criterion is not the religion of its citizens.
3. Which Muslim Countries today are Dar al-Islam?
Out of the Muslim countries of today, there is not a single country or state where Islamic laws are exclusively implemented in ruling and life's affairs; therefore all of them are considered Dar al-Kufr although their citizens are Muslims.
4. What is The Muslims Duty towards His Country?
Islam makes it a duty upon all Muslims to work to change their countries from Dar al-Kufr to Dar al-Islam, and this can be achieved by establishing the Islamic State i.e. the Khilafah, and by electing a Khaleefah and taking a bay'ah on him that he will rule by the Word of Allah (Subhaanahu Wa Ta'Ala) i.e. he will implement Islamic laws in the country where the Khilafah has been established. Then the Muslims should work with the Khilafah to combine the rest of the Islamic countries with it, hence the countries will become Dar al-Islam and they will then carry Islam to the world through invitation and jihad.
5. What is the Khilafah
The Khilafah is the global leadership for all the Muslims in the world. Its role is to establish the laws of the Islamic Shari‘ah and to carry the da‘wah of Islam to the world.
http://www.risala.org/content/view/89/32/
"invitation and Jihad" Convert or DIE! Pretty much incompatible with individuality, liberty, freedom, democracy and everything we value in the US.