Can my government ban travel to certain countries?

The short answer is YES they can. However, it is not technically a ban on travel, you will just find it impossible to purchase tickets to certain countries.

Generally speaking any nation that includes in its Constitution any mention on the right to freedom of travel/mobility limits that only to travel within the nation. You will find that in most cases you have no constitutional right to travel abroad. Most governments routinely issue Travel Advisories and Travel Warnings to other countries when the political situation or lack of public security are such that they can't guarantee the safety of their citizens who travel to those nations. The next step in this process is to ban travel. Brazil has been on both the Canadian and USA Travel Advisory list for quite some time now. Should they ban travel? I'm beginning to wonder if this wouldn't be a prudent and avisable thing for them to do. The Brazilian government certainly isn't in control of the situation anymore.

Just go to any travel agency in the USA or Canada and ask for tickets to Somalia or Syria and see what happens. Or see the reception you get at Customs & Immigrations when you return from your next trip abroad with stickers from Iran, Iraq, Botswana, Yemen, Columbia, etc. plastered all over your luggage.

Canada Travel Advisories:  http://travel.gc.ca/travelling/advisories

USA Travel Advisories:  http://travel.state.gov/travel/cis_pa_t … _1764.html
(note: Brazil has now been added to this list)

If the USA were to issue a ban on travel to Brazil before June 2014 I'm sure several other nations would quickly do likewise. This would kill both the 2014 World Cup and 2016 Summer Olympic Games, something that the Brazilian authorities obviously give little thought to.