"must entail" is a correct and commonly used phrase in written English.
It is used to express an obligation or requirement. For example, "Serving in the military must entail a great deal of sacrifice."
A growing chorus argues that this must entail some form of joint liability for countries' debts.
If politics is the art of the possible, then radicalism must entail the desire to imagine other possibilities.
Effective revamping of the congeries of rival committees and subcommittees must entail an upending of most lawmakers' personal power bases.
"Any hope of curbing the North's nuclear weapons program must entail like restrictions on the South," Mr. Tobey said.
Besides, Mr. Tobey said, "any hope of curbing the North's nuclear weapons program must entail like restrictions on the South".
Our friend, duly impressed and thinking of the arduous field work such research must entail, asked the naturalist how he knew where to hunt for the animals.
"This must also entail religious groups working towards the ideals of the UN, in terms of human rights, fairness and justice for all men and women".
Many Germans feared, and some Swedish diplomats now believed, that a final settlement must probably entail the deposition of the German emperor Ferdinand II and the election of Gustav as emperor in his place.
Our displaced anxiety must partly entail a fear of being tricked (mistaking a tracing for a freehand drawing) and, more particularly, a fear of technology: a concern that what makes us human is being sacrificed to the brilliance and reliability of the machine.
There is a common misconception that domestic violence must always entail some form of physical abuse -- this is far too simplistic of a definition.
He warned, for example, that if war came, soldiers would "be subject to the unfair handicap and the certainty of increased loss of life which inferiority in armament and shortage of ammunition must inevitability entail".
