English doesn't have a formal grammatic future tense. What we used to have was the subjunctive mood, which lumped the future in with hypothetical statements and other uncertainties. This is what has shifted to modals.benhall.1 wrote: The example you give there, David, strikes me as being a simple use of the future tense.
For an example of the subjunctive in use, consider the following:
In UK usage, a headline might say, "the law requires that there is a lifejacket for every passenger." In North American english, "the law requires that there be a lifejacket for every passenger" would be more correct. The latter is the subjunctive, holding on by the skin of its teeth.