The chart shows that the discretionary actions are the largest in the US (the blue/grey column) measured as % of GDP. However, the overall fiscal stimulus is larger in other countries because of the presence of large automatic stabilizers. The size of the automatic stabilizers is related to the size of the government and the welfare state.
In the case of Ireland and Iceland, the governments have taken discretionary actions to reduce the size of the deficit, which is the result of a deep recession and the automatic stabilizers (i.e. the government has either increased some taxes or reduced government spending). This "contractionary" fiscal policy is not what their economies need but it is the only way to avoid a loss of confidence.