The think-tank Henry Jackson Society has reported a 'clear and growing link' between Islamist organisations preaching violence in the UK and foreign state funding. It has called for a public inquiry into extremism bankrolled by several Gulf States. Saudi Arabia and Iran are responsible for much of the foreign funding of extremism in the UK; Saudi Arabia has spent millions on exporting its conservative Wahhabi Islam to Muslim communities since the 1960s. Funding takes the form of endowments to mosques and Islamic educational institutions which host radical preachers and distribute extremist literature. Running parallel with this is the fact that the Saudis are one of the main buyers of UK-made arms, with the UK Government approving £3.5bn-worth of arms exports licences to the Gulf state recently and British ministers cultivating trading relationships as the UK looks for post-Brexit trading partners.