As has previously been mentioned, FDI is subject to changes that affect the attitude towards them in many countries. There is tension exists between the commitment to freedom of FDI and the right of the state to ensure that certain legitimate public interests and goals can be fully implemented. This may lead to the protection of certain strategic sectors of the economy of the country or flagship firms from foreign investment on national security, national essential security interests or related grounds.

M&As are one of the more popular ways to gain a presence in the host state via FDI. In comparison to greenfield projects, M&As offer the foreign investor an ideal way to gain control over critical technology and know-how, as well as sensitive information pertaining to the existing client base and market share. M&As have a significant impact on the economy of the host country and can thus potentially create greater national security concerns than other investment operations, especially when the investment is sovereign driven.

Greenfield investment has traditionally been considered by some states in more positive terms than M & A operations. Greenfield projects create new production capacity in the host country. M&As, on the other hand, are viewed with suspicion, in so far as they can sometimes be the result of fire-sales of domestic assets as a consequence of the economic crisis or as a consequence of the enormous economic power of the foreign acquirer that may in some cases be backed by a foreign state. They do not add any productive capacity, can involve job losses, and can lead certain areas of the economy or critical infrastructures coming under foreign control, thus threatening national security.

However, this positive attitude towards greenfield projects is also starting to change in some countries. For instance, the Russian space agency Roscosmos wanted to build around half a dozen of global positioning systems monitoring stations in the US in 2013. This spread concerns in the US about their potential to be used for espionage. It also fuelled the drive to amend the current system for evaluating FDI proposals on national security grounds – changes were made by CFIUS to extend its jurisdiction to include ‘greenfield’ investment.