IN Paris, it's been the summer of the bomb. And the Bomb. Average Parisians are most concerned about the five terrorist bombs that were planted in or around the capital in the past six weeks. But the topic chewing up the most fax paper in the presidential palace is the eight nuclear bombs slated to go off on a Pacific atoll 11,178 miles away. While the French response to bombs at home could become a model for combating international terrorism, France's defense of its decision to resume nuclear tests in the Pacific has drawn international protests. Debates have already begun over what went wrong. Protest marches in Papeete, Tahiti - the closest major city to the test site - have drawn thousands of demonstrators and scores of politicians. French Foreign Minister Herve de Charette blasted the presence of Swedish and Japanese ministers among the protesters as ''inexcusable.'' Japanese Finance Minister Masayoshi Takemura didn't flinch. ''I think that such a reaction by the French government makes my visit worth the effort,'' he said on Sept. 5. Other opponents of French testing express amazement at how ineffectual French officials have been in bringing their own case to the public. ''We couldn't have scripted this protest,'' said an organizer for the environmental group Greenpeace in Australia, who asked not to be identified. He said the group provoked France into seizing Rainbow Warrior 2 in July - exactly 10 years after French agents bombed the original Rainbow Warrior as it was about to sail for Mururoa atoll, the test site. On Sept. 5, New Zealand called in the French ambassador to voice concern over the use of force by French commandos in seizing two Greenpeace ships near Mururoa Sept 1. ''It's a difficult and emotional issue. We've had to explain everything 15 times,'' says presidential spokeswoman Catherine Colonna. ''Many who claim to oppose us are just not acting in good faith.'' ''President Chirac's immediate entourage seriously underestimated the political consequences of this decision,'' says Frederic Bozo of the French Institute of International Relations in Paris. ''They didn't use the information the Foreign Ministry was giving them on the likely response in the Pacific and especially in Europe.'' Since Charles de Gaulle initiated France's nuclear program, control of the arsenal has been viewed in France as a presidential prerogative. When current President Jacques Chirac announced June 13 that France would resume testing, he said the decision was ''irrevocable.'' ''For the last 20 years, French public opinion on nuclear questions has followed the actions of the president,'' Mr. Bozo says. ''This is not the case in other countries, where politicians know they need to explain their nuclear decisions to the public.'' In a televised interview Sept. 5, Mr. Chirac said France may conduct fewer tests than planned and that the tests could be completed before the designated May 31, 1996, end date. French officials hope the results of recent tests by the Vienna-based International Atomic Energy Agency will defuse criticism. The IAEA coordinated the analysis of samples from the Mururoa test site in the fall of 1994. The results, released Sept. 1, show no abnormal levels of radioactivity. ''It's amazing that international labs were even able to measure radioactive elements, there was such a small degree of these substances,'' says Dennis Marty, deputy director of the French Atomic Energy Commission. Last month, the French foreign ministry asked the IAEA to measure radioactivity after the upcoming nuclear tests. IAEA officials have yet to respond. ''We did similar tests after the last French tests in 1991,'' says IAEA spokesman David Kyd in Vienna. ''We didn't find anything abnormal then, either. But now the political context is different.... If we did [conduct new tests], the tests would have to be done in a serious fashion, not just a quick look-see.''