"cannot be ensured" is grammatically correct and can be used in written English.
Example: The success of this project cannot be ensured, as there are many factors that are beyond our control.
"It cannot be ensured that the excessive deficit will be corrected by 2013".
So without BMD, security for NATO in Europe cannot be ensured.
A peaceful, just, stable and sustainable international order cannot be ensured by the private sector, whose driving force is short-term profit.
"Without peace and security in Afghanistan, peace and security in Pakistan cannot be ensured," he told reporters, adding that he had come to Kabul to formally invite Mr. Karzai to Pakistan.
However, when forecasting different agricultural commodities, the effects cannot be ensured and overfitting may happen.
Therefore, the reliability of these methods cannot be ensured while the sensors' state is abnormal.
(2) The security cannot be ensured when DMND uses application names in the data communication process.
However, when considering only energy efficiency aspects on the energy management strategy, an economical viable solution cannot be ensured.
In these countries water disinfection methods are not usually applied or cannot be ensured an appropriate effectiveness.
Students' active engagement in such scenarios cannot be ensured, due to the unexpected nature of such infrequent events.
