Convergence towards a European strategic culture? A constructivist framework for explaining changing norms.

The article contributes to the debate about the emergence of a European strategic culture to underpin a European Security and Defence Policy. Noting both conceptual and empirical weaknesses in the literature, the article disaggregates the concept of strategic culture and focuses on four types of norms concerning the means and ends for the use of force. The study argues that national strategic cultures are less resistant to change than commonly thought and that they have been subject to three types of learning pressures since 1989: changing threat perceptions, institutional socialization, and mediatized crisis learning. The combined effect of these mechanisms would be a process of convergence with regard to strategic norms prevalent in current EU countries. If the outlined hypotheses can be substantiated by further research the implications for ESDP are positive, especially if the EU acts cautiously in those cases which involve norms that are not yet sufficiently shared across countries

The field high-amplitude SX Phe variable BL Cam: results from a multisite photometric campaign. II. Evidence of a binary - possibly triple - system

Short-period high-amplitude pulsating stars of Population I ($\delta$ Sct stars) and II (SX Phe variables) exist in the lower part of the classical (Cepheid) instability strip. Most of them have very simple pulsational behaviours, only one or two radial modes being excited. Nevertheless, BL Cam is a unique object among them, being an extreme metal-deficient field high-amplitude SX Phe variable with a large number of frequencies. Based on a frequency analysis, a pulsational interpretation was previously given. aims heading (mandatory) We attempt to interpret the long-term behaviour of the residuals that were not taken into account in the previous Observed-Calculated (O-C) short-term analyses. methods heading (mandatory) An investigation of the O-C times has been carried out, using a data set based on the previous published times of light maxima, largely enriched by those obtained during an intensive multisite photometric campaign of BL Cam lasting several months. results heading (mandatory) In addition to a positive (161 $\pm$ 3) x 10$^{-9}$ yr$^{-1}$ secular relative increase in the main pulsation period of BL Cam, we detected in the O-C data short- (144.2 d) and long-term ($\sim$ 3400 d) variations, both incompatible with a scenario of stellar evolution. conclusions heading (mandatory) Interpreted as a light travel-time effect, the short-term O-C variation is indicative of a massive stellar component (0.46 to 1 M_{\sun}) with a short period orbit (144.2 d), within a distance of 0.7 AU from the primary. More observations are needed to confirm the long-term O-C variations: if they were also to be caused by a light travel-time effect, they could be interpreted in terms of a third component, in this case probably a brown dwarf star ($\geq$ 0.03 \ M_{\sun}), orbiting in $\sim$ 3400 d at a distance of 4.5 AU from the primary.Comment: 7 pages, 5 figures, accepted for publication in A&

Spectropolarimetry of the Type II Supernovae 1997ds, 1998A, and 1999gi

We present single-epoch spectropolarimetry of the Type II supernovae (SNe II) 1997ds, 1998A, and 1999gi. SN 1997ds and SN 1998A were both observed during the early photospheric phase, while spectropolarimetry of SN 1999gi was obtained near the start of the transition to the nebular phase. Uncorrected for interstellar polarization (ISP), SN 1997ds is characterized by p_V = 0.85 +/- 0.02%, SN 1998A has p_V = 0.24 +/- 0.05%, and SN 1999gi is polarized at p_V = 5.72 +/- 0.01%. The low continuum polarization inferred for SN 1997ds and SN 1998A and the amplitude of polarization modulations across strong line features are consistent with those measured at similar epochs for SN 1987A and the Type II-plateau SN 1999em, and supports the growing consensus that core-collapse events with hydrogen envelopes substantially intact at the time of explosion are not significantly aspherical during the early photospheric phase. The spectral shape of the high continuum polarization of SN 1999gi closely resembles a ``Serkowski'' ISP curve, and is inconsistent with the wavelength-independent nature of electron scattering expected for an aspherical SN atmosphere. Since Galactic reddening is minimal along this line-of-sight, the majority of the observed polarization in SN 1999gi is believed to be due to ISP of the host galaxy, although significant (up to p = 2%) intrinsic polarization cannot be ruled out. The potential power of SN spectropolarimetry to study the properties of interstellar dust in external galaxies is described and applied to the SN 1999gi data, where it is shown that if the polarization is indeed predominantly interstellar in origin, then R_V = 3.0 +/- 0.2 for the dust along this line-of-sight in NGC 3184.Comment: 34 pages (13 Figures, 2 Tables). Accepted by PAS