We ordinarily associate the mitzvah of lighting ner Chanukah with the concept of pirsumei nisa: a chance to publicize the great miracle that Hashem performed for us in those days. It would therefore be logical to assume that the more public we can make this mitzvah, the better. So perhaps the lighting should be outside. However, the Gemara qualifies this notion of pirsumei nisa with the following statement: 

תנו רבנן: נר חנוכה מצוה להניחה על פתח ביתו מבחוץ. אם היה דר בעלייה - מניחה בחלון הסמוכה לרשות הרבים. ובשעת הסכנה - מניחה על שלחנו, ודיו

Our rabbis taught: The candle of Chanukah should be lit at the entrance of one’s home on the outside. If one lives on a higher floor, one places it in the window closest to the public thoroughfare. In times of danger, one may place it on the table and that is sufficient.

Shabbat 21b

During times of danger, we can fulfill the mitzvah by lighting inside the home on our table. While the parameters and applications of this ruling are subject to halachic debate, there is a subtle message in this halachic ruling as well. 

In the classic work of Chassidus, the Bnei Yisaschar (Kislev 3:38), Rabbi Tzvi Elimelech Spira of Dinov (c. 1783–1841), writes that the word v’dayo — and that is sufficient — seems superfluous. The Gemara could have just ended by saying “place it on the table.” Rather, the word v’dayo tells us that those outside cannot properly understand or appreciate the message of the Menorah and the miracle it represents. They will deride it. It is sufficient to light for those people in your home. The message of Hashem’s great miracles and omnipotence is only needed to be understood by those in the home; those who will appreciate it and use it to further the message of Hashem and His Torah in the world. 

The challenge of living in a world full of people who don’t understand the values of Torah or see G-d’s hand in daily living is great. But recognize that it is up to those around the table, who are in the house, to be the ambassadors who will slowly bring back the days of true pirsumei nisa — a day where everyone sees and understands the large and small miracles that Hashem has and continues to bestow upon us.