"secure independence" is correct and usable in written English.
You could use this phrase to express the idea of achieving freedom from something. For example, "The people of this nation fought to secure their independence from colonial rule."
In their campaign to secure independence from France, the Algerian National Liberation Front resorted to terror.
Relations between Moldova and Transdniestria remained strained over the latter's attempt to secure independence, a goal the majority of voters there supported again in a referendum in 2006.
While the unionists have to win every time to preserve the UK, the Nationalists only have to win once to secure independence.
Around 20 years ago, I was involved in the process of negotiations that followed the Madrid conference, an early attempt to start a peace process, in an effort to secure independence for Palestine and the rights of its people.
The document has been associated with the coronations of Pippin in 754 and Charlemagne in 800, as well as with papal efforts to secure independence from the Byzantine Empire or to undermine Byzantine territorial claims in Italy.
Chao Anu, also called Anou, Anouvong, or Anuruttharat (born 1767 died 1835, Bangkok, Siam [Thailand]) ruler of the Lao kingdom of Vientiane who tried unsuccessfully to secure independence for central and southern Laos from its Siamese overlords.
Nonetheless, several proposals have been made for securing strong independence and solving the Drowning Problem.
Securing strong independence makes the systems very sensitive to the exact form in which the default information is stored.
Within a decade, Sudan secured independence.
In the past 20 years, only four countries have secured independence: Timor-Leste, Montenegro, Kosovo and South Sudan.
He devoted his first term in office to securing independence from Britain and used that prestige to win five more elections.
