Everyone is opposed to terrorists shooting innocent people or blowing others - and themselves - apart. Except the fanatics who feel this is their calling.
We know what terrorism is and how it thrives on fear. We see and hear politicians ramping up these fears with war-like rhetoric and talk of shortcuts to basic freedoms. It suits them and the multi-national corporates to sell us fear as there is political traction and financial gain to be made from encouraging citizens to live in fear. Events are cancelled, nations go into martial mode and whole sections of society become easy scapegoats. But we must resist the temptation to go where this leads as this means the terrorists are winning.
To oppose terrorism we need to define and name the opposite of terror. The various "isms" tend to have a bad name and are often tainted by history - fascism, fundamentalism, triumphalism, fanaticism, totalitarianism, racism and a new one "Donald Trumpism".
Pacifism is not right as an opposite to terrorism. It carries a "do nothing" rather than a "do something" connotation. The Daleks were wrong and resistance is not useless.
We have optimism - meaning we live in the "best of all possible worlds" but the pejorisms people (severe pessimism) would dispute that creating a schism leading to further absurdisms. The followers of apocalypticism would really think the end was nigh and find themselves agreeing with fideism. Terrorism cannot be countered by fatalism, cynicism or sarcasm or stoicism - it requires the linking of humanitarianism with mutualism working on gradualism to oppose ignorantism.