Cooperation on the front end of the nuclear fuel cycle has by and large referred specifically to uranium enrichment. In this regard, there are two approaches towards front end cooperation: a state can invest and purchase stakes in a foreign enrichment facility to enhance assurance to enrichment services, or it can site a multinational facility domestically. With regards to the latter option, the domestic facility theoretically provides the greatest level of supply assurance as it lies within national borders, while inviting multinational participation in the facility is intended to allay proliferation concerns by the international community.