The phrase "cornerstone of strategy" is correct and usable in written English.
You could use it to refer to an idea or concept that is fundamental to a strategy or plan. For example, "Reducing costs was the cornerstone of our company's growth strategy."
Activation of these pools of latent HIV-1 by latency reversing agents (LRA) that induce viral expression is one of the cornerstones of strategies to eliminate latency by "kick and kill".
The AT&T project was a cornerstone of that strategy.
He maintained a formal alliance with the Frondizi followers, but the cornerstone of his strategy was an understanding with the largest non-Peronist party, the Radicals.
The Tribune Company made it clear last week that a cornerstone of its strategy in buying the Times Mirror Company would be to use its print journalists for the news reports of its television and radio stations and its Web sites.
The pursuit of the prosecutable lie has been a cornerstone of F.B.I. strategy, especially in its post-2001 incasnanion anti-terrorismrorism agency, and Comey wastes no time reflecting on its tenuous relationship to actual crime, or actual justice.
The culture has come to favor — even demand, if you consider the middle-class dependence on home equity and 401 k)s and 529s — financial speculation as the cornerstone of a strategy for prosperity, at the urging of the government.
This strength needs to be the cornerstone of a strategy for peace — helping Afghanis take the lead in building accountability and legitimacy from the bottom up, even as corruption and chaos prevail at the top, for a while.
He was one of the first to recognize the importance of favorable matchups — now a cornerstone of game strategy — and that drove his early recognition of how critical speed would become, particularly in his beloved vertical passing game.
