I feel that Sanatana Dharma and Hinduism are synonyms. But it's never an important enough point for me to argue incessantly about. Doing daily sadhana, attempting to live according to the yamas and niyamas, meditating (if you can) going on pilgrimage, being kind to one's brothers and sisters ... in other words, taking action over discussion about action, limiting anger, well these things are actually important. The action outweighs the discussion by about 100 to 1.
I appreciate the intent, but let me have your take on a personal situation that happened not long ago:
A Catholic friend of mine was chatting with me and I mentioned Dharma (meaning Buddhadharma) a few times. He eventually warned me to be careful not to be caught by Hindus talking about Buddhism as if it were Dharma (he actually complemented that with "or at least as Sanatana Dharma"), because it might be seen as unduly appropriating the term.
My attempts at explaining that while Sanatana Dharma is indeed Hinduism and not Buddhism, but Dharma by itself is a well accepted enough word for use by Buddhism, were cut short by his claim that Hindus had accepted Catholicism as an Universal Religion. He went on to explain that St. Francis of Assisi's teachings were branded as Sanatana Dharma by Indian locals, which he saw as support for his conclusion.
Personally, I think that either him or whoever taught him the tale were confusing the first and second meanings of Sanatana Dharma, a situation which I view as unfortunate and at least potentially abusive. An important part of the strength of Dharma as a religious approach is
avoiding such general statements on whole multitudes of practicioners while still acknowledging the wisdom and good work of religious teachers and practicioners on a case-by-case basis.
His misunderstanding, unintentional and well-meaning as it may have been, is IMO a failure to take advantage of that important strength, if not worse.
As you may tell, I feel that such a situation illustrates a good reason to be clear and give context when we talk of Sanatana Dharma.
What do you think?