"The ever-evolving technology of war" means that, in the absence of a peace deal, "it will be increasingly difficult to guarantee the security of Israeli families".
It's very difficult to guarantee that you won't ding your fender in a minor accident, and cheaper to pay for the event than to hedge against it.
More recently, top officials in the state of Rajasthan, of which Jaipur is the capital, argued that it would be difficult to guarantee Mr. Rushdie's security.
Mark Walport, director of the Wellcome Trust, welcomed the review and said that it was always difficult to guarantee the usefulness of research in advance.
When any single source of fuel accounts for even a third of the power flowing into a grid, the security of that system is difficult to guarantee.
It is a primary function of society to set up the framework in which legitimate contracts, freely entered into, may be enforced, a state of affairs much more difficult to guarantee in the state of nature and outside civil society.
Johnson also said it was difficult to guarantee the EU question will be settled forever by the referendum, even though David Cameron has ruled out the idea of a second poll in future.
However, a fast global convergence is difficult to guarantee.
Moreover, the transmission time is greatly prolonged, and reliability is difficult to guarantee.
However, it seems difficult to guarantee such conditions in a big data environment.
It is difficult to guarantee that all possible situations are tested when evaluating a location method.
