Although recent levels of tensions between Saudi Arabia and Iran have increased, the history of regional hostility between the two countries is quite old. Both the countries in and outside the Middle East have dominant personal friends and different enemies of the enemy.
Saudi Arabia
Sunni main monarchy is known as the birthplace of Islam religion. Most of the important structures of the Islamic world are located in the country.
Saudi Arabia, one of the world's leading oil exporters and oil exporting nations, is one of the richest countries in the world.
The harsh position of US President Donald Trump is behind Saudi Arabia's recent hostility against Iran. In addition, the Saudi Prince, Muhammad bin Salman, has declared war against the Houthi rebels in Yemen.
Saudi Arabia is complaining that Iran has provided equipment to Hutheh, although Tehran has rejected the claim. Saudi Arabia again supports Iranian rebels and wants to oust President Bashar al-Assad
Saudi Arabia fears Iran will dominate the Middle East, and the country is opposed to increasing the influence of Shi'a in this region.
One of the best decorated armies in the Middle East is Saudi Arabia. The country is the world's largest arms importer and has two hundred and twenty seven thousand soldiers.
Iran
In 1979, the Islamic Republic of Iran was established, the monarchy was overthrown, and religious leaders took political control under the leadership of Ayatollah Khomeini. 80% of Iranians are Shi'a.
The main strength in this region in Iran, and their influence has increased remarkably in the last decade - especially after the overthrow of Saddam Hussein in Iraq.
Iran is supporting Syrian President Bashar al-Assad - in his fight against opposition groups and the Islamic State. Iran's Islamic Revolutionary Guards have played a major role in preventing the advance of Sunni jihadists in Iraq and Syria.
Iran believes that Saudi Arabia is trying to destabilize Lebanon The Shiite movement called the Hejbollah, supported by Iran, is part of Lebanon's government.
The United States thinks Iran is their main opponent.
It is believed that Iran has the most advanced missile in the region. There are 5,34,100 soldiers in the Iranian army.