Belloc was a liberal? Well, yes, technically he was. Indeed, he sat as a Liberal Member of Parliament for the constituency of Salford South from 1906 to 1910. But, it is difficult to wrap one's head around the fact because of what 'liberalism' has become.
His 'liberalism' was opposition to the ruling oligarchy of Britain and he left Parliamentary politics when he realised that he could fight the oligarchy from a better vantage point outside party politics.
From the ChesterBelloc Mandate
There is, again, a theory in economics and politics directly the opposite of our own, cutting at the root of our most obvious principles; and it is growing daily. It involves an attack upon personal production, personal accumulation, and consequent personal possession: a theory which makes the individual and all the individual virtues of small account, and desires to emphasise rather the vague qualities of a State.
It would dissolve thrift, and self-control, and the personal honour which keeps a contract sacred, and replace them by a State reserve, by State control, and by a State system, releasing men from the burden of private rectitude. It is a theory which is absolutely certain to find stronger and stronger support as our economic system develops, unless it is met by an unflinching adherence to those older political principles which have strength left in them to shape the economic system itself. Though it will be dealt with later in this essay, it is worthy of consideration for a moment in these introductory sentences, because it forms so admirable an example of those clear hypotheses that frequently succeed in transforming the politics of a nation.
This new theory is simple, consistent, and strong. Just as the Jingo finds a substantial support in the actual facts of empire and in the continued immunity awarded to broken pledges and to unprovoked attacks, so the Socialist finds his support in the actual facts of the present system of economics, in the divorce of personality from production, and in the partial achievement of that centralisation of capital which is his goal. He has upon his side all the potential force of a majority which has forgotten what property means, and even of a considerable minority so used to great accumulations as to have equally lost the personal sentiment of attachment in regard to it. He has the additional strength of morally occupying the defensive, saying, "Here is the present system, large capital in few units employing many wage-earners. I believe it cannot be fundamentally changed, yet by removing a merely sentimental factor which does not concern the wealth itself, I shall be able to use that wealth to far greater advantage for the community."
Is not this theory, with its rigid conclusions, its obvious postulates, and its material surroundings, precisely such as must command, when once it has penetrated the electorate, a wide and an enthusiastic following? Is not that other force—the desire of mere conquest—simple and strong? They are but two of the parties most prominent among the many political opponents of Liberalism; and surely the moral for us to draw from the methods of such antagonists is that only by an attitude equally frank and by an appeal to sentiments equally widespread, can we hope to continue the work of the early leaders of reform. We must be convinced that, whatever adaptation may do in the details of working, the main force in any political movement is some clear and abstract principle clearly understood and continually applied.