All of our houses, minus Sig Chi, have international students, we do have an abnormally high internat'l rate for a school our size. Many are more than willing to get involved, but just like any pledge, you need them to know that they have to be at events. Sometimes the cultural barrier can make this difficult.
About actives studying abroad, again my school has about 50% students study abroad so a little higher than normal, but we have a seperate configuration for dues to take the strain off the chapter as we only have 30 actives. Right now of the 30 5 are abroad. So they pay their nat'l fees and then a 1/4 of local fees, that way they can go abroad and we can still have the support.
The experience of studying abroad is so critical to liberal arts experience, we try not to hinder the opportunity.