In at least two different places in his diary (I haven't finished reading it yet, so there might be others as well) Henri Nouwen comments on events taking place in other parts of the world. He writes with feeling of events in Chile and Africa, and about testimonies to persecution and to shortages of basic foods in these distant parts of the world. The depth of feeling with which Fr Nouwen writes makes an impression on the reader.
For the monk, more than for the lay person, there might be the sense that events such as these are "distant". It is easy to see them as not being something we should worry about; instead we should focus on our own lives, and the fulfilling of God's will in our own lives.
When discussing the question raised by this, it is easy to play these two polarities off against each other. In the Christian life, this might be expressed by a tendency to let one's commitment to "the third world" provide a gloss over things that are wrong in our immediate living of Christian life in our own circumstances. The dichotomy is one that isn't as apparent now as it was perhaps in the 1960's and 1970's.
An authentic Christian response is a "both-and" rather than an "either-or". Perhaps primarily, we should focus on living in our own, immediate circumstances. The challenges that this presents to us represent the vocation that, in the providence of God, is our particular one. Our first call, then, is to answer that vocation, and so achieve a fruitfulness in the Christian life. However, this does not mean that we should exclude that part of Christian living that might be expressed by the word "solidarity".
If we understand the monastic life as Christian living taken to its most radical form, and so see it as a model for all Christian living, it can teach us the lesson of this "both-and" very well. The monk is confined to one place - the monastery - which prompts the focus on living the Christian life in the place where he finds himself. But, at the same time, the monk can be extraordinarily well informed about what is going on in the wider world. Which opens up to the monk the possibilities of solidarity in his prayer and penance.